Geominerals/Hydroxides

From Wikiversity
Jump to navigation Jump to search

Hydroxide minerals generally contain more than 25 molecular % OH. But, some classification systems include minerals as hydroxides if they are found to contain hydroxides.

Solutions[edit | edit source]

Schematic representation is of the bihydroxide ion. Credit: .{{free media}}

The hydroxide ion is a natural part of water because of the self-ionization reaction in which its complement, hydronium, is passed hydrogen:[1]

H
3
O+
+ OH
⇌ 2H
2
O

The equilibrium constant for this reaction, defined as

K
w
= [H+
][OH
], where [H+
] denotes the concentration of hydrogen cations and [OH
] the concentration of hydroxide ions.

has a value close to 10−14 at 25 °C, so the concentration of hydroxide ions in pure water is close to 10−7 mol∙dm−3, in order to satisfy the equal charge constraint. The pH of a solution is equal to the decimal cologarithm of the hydrogen cation concentration; strictly speaking pH is the cologarithm of the hydrogen cation. The pH of pure water is close to 7 at ambient temperatures. The concentration of hydroxide ions can be expressed in terms of pOH, which is close to (14 − pH), pOH signifies the minus the logarithm to base 10 of [OH
], alternatively the logarithm of 1/[OH
], so the pOH of pure water is also close to 7. Addition of a base to water will reduce the hydrogen cation concentration and therefore increase the hydroxide ion concentration (increase pH, decrease pOH) even if the base does not itself contain hydroxide. For example, ammonia solutions have a pH greater than 7 due to the reaction NH3 + H+NH+
4
, which decreases the hydrogen cation concentration, which increases the hydroxide ion concentration. pOH can be kept at a nearly constant value with various buffer solutions.

In aqueous solution[2] the hydroxide ion is a base in the Brønsted–Lowry sense as it can accept a proton, in this context proton is the term used for a solvated hydrogen cation, from a Brønsted–Lowry acid to form a water molecule. It can also act as a Lewis base by donating a pair of electrons to a Lewis acid. In aqueous solution both hydrogen and hydroxide ions are strongly solvated, with hydrogen bonds between oxygen and hydrogen atoms. Indeed, the bihydroxide ion H
3
O
2
has been characterized in the solid state. This compound is centrosymmetric and has a very short hydrogen bond (114.5 pm) that is similar to the length in the bifluoride ion HF
2
(114 pm).[3] In aqueous solution the hydroxide ion forms strong hydrogen bonds with water molecules. A consequence of this is that concentrated solutions of sodium hydroxide have high viscosity due to the formation of an extended network of hydrogen bonds as in hydrogen fluoride solutions.

In solution, exposed to air, the hydroxide ion reacts rapidly with atmospheric carbon dioxide, acting as an acid, to form, initially, the bicarbonate ion.

OH + CO2HCO
3

The equilibrium constant for this reaction can be specified either as a reaction with dissolved carbon dioxide or as a reaction with carbon dioxide gas (see carbonic acid for values and details). At neutral or acid pH, the reaction is slow, but is catalyzed by the enzyme carbonic anhydrase, which effectively creates hydroxide ions at the active site.

Solutions containing the hydroxide ion attack glass. In this case, the silicates in glass are acting as acids. Basic hydroxides, whether solids or in solution, are stored in airtight plastic containers.

The hydroxide ion can function as a typical electron-pair donor ligand, forming such complexes as tetrahydroxidoaluminate [Al(OH)4]. It is also often found in mixed-ligand complexes of the type [MLx(OH)y]z+, where L is a ligand. The hydroxide ion often serves as a bridging ligand, donating one pair of electrons to each of the atoms being bridged. As illustrated by [Pb2(OH)]3+, metal hydroxides are often written in a simplified format. It can even act as a 3-electron-pair donor, as in the tetramer [PtMe3(OH)]4.[4]

When bound to a strongly electron-withdrawing metal centre, hydroxide ligands tend to ionise into oxide ligands. For example, the bichromate ion [HCrO4] dissociates according to

[O3CrO–H] ⇌ [CrO4]2− + H+

with a pKa of about 5.9.[5]

Abhurites[edit | edit source]

Brownish tabular crystals of abhurite are from Shipwreck "Hydra", South coast of Norway. Credit: Thomas Witzke.{{free media}}

Abhurite (IMA symbol: Abh[6]) is a mineral of tin, oxygen, hydrogen, and chlorine with the formula Sn
21
O
6
(OH)
14
Cl
16
[7][8] or Sn
3
O(OH)
2
Cl
2
.[9] It is named after its type locality, a shipwreck with tin ingots at Sharm Abhur, a cove near Jeddah in the Red Sea. Abhurite forms alongside other tin minerals like romarchite and cassiterite.[10]

Abhurite formed on tin materials when in contact with sea water. The mineral was described in 1977 from a shipwreck near Hidra Island, Norway, where it occurred on pewter plates. However, that report was not recognized by the IMA, International Mineralogical Association.[8] Along with Sharm Abhur and the shipwreck near Hidra Island, abhurite was found on tin ingots in the Uluburun shipwreck. On the ingots, it was found with other tin minerals like cassiterite and romarchite, and calcium carbonate minerals like calcite and aragonite.[11]

Actinolites[edit | edit source]

Actinolite, acicular form, is from Montijos Quarry, Leiria District, Portugal. Credit: Didier Descouens.{{free media}}

Actinolite (IMA symbol Act[6]) has the chemical formula Ca
2
(Mg2+
4.5-2.5
Fe2+
0.5-2.5
)
Si
8
O
22
(OH)
2
, is an amphibole silicate mineral. The name actinolite is derived from the Greek word aktis (ἀκτίς), meaning "beam" or "ray", because of the mineral's fibrous nature.[12]. Actinolite is an intermediate member in a solid-solution series between magnesium-rich tremolite, Ca
2
(Mg2+
5.0-4.5
Fe2+
0.0-0.5
)
Si
8
O
22
(OH)
2
, and iron-rich ferro-actinolite, ☐Ca
2
(Mg2+
2.5-0.0
Fe2+
2.5-5.0
)
Si
8
O
22
(OH)
2
. Mg and Fe ions can be freely exchanged in the crystal structure. Like tremolite, asbestiform actinolite is regulated as asbestos.

Actinolite is commonly found in metamorphic rocks, such as contact aureoles surrounding cooled intrusive igneous rocks. It also occurs as a product of metamorphism of magnesium-rich limestones.

The old mineral name uralite is at times applied to an alteration product of primary pyroxene by a mixture composed largely of actinolite. The metamorphosed gabbro or diabase rock bodies, referred to as epidiorite, contain a considerable amount of this uralitic alteration.

Acuminites[edit | edit source]

Acuminite (IMA symbol: Acu[6]) is a rare halide mineral of with chemical formula: SrAlF
4
(OH)
·(H
2
O
). Its name comes from the Latin word acumen, meaning "spear point". Its Mohs scale of mineral hardness rating is 3.5.

Acumenite has only been described from its type locality of the cryolite deposit in Ivigtut, Greenland.[13]

Adamites[edit | edit source]

Yellow-green adamite is in limonite. Credit: Robert M. Lavinsky.{{free media}}
Adamite is on limonite from the Gold Hill District Tooele County, Utah, USA - scale at bottom is approx. 2.5 cm. Credit: Rock Currier.{{free media}}

Adamite (IMA symbol: Ad[6]) is a zinc arsenate hydroxide mineral, has the chemical formula Zn
2
AsO
4
OH
, and is a mineral that typically occurs in the oxidized or weathered zone above zinc ore occurrences.

Adamite occurs as a secondary mineral in the oxidized zone of zinc- and arsenic-bearing hydrothermal mineral deposits. It occurs in association with smithsonite, hemimorphite, scorodite, olivenite, calcite, quartz and iron and manganese oxides.[14]

Adelites[edit | edit source]

Pinkish crystal aggregates of adelite are from the Franklin deposit in Ogdensburg, New Jersey. Credit: David Hospital.{{free media}}

The rare mineral adelite, (IMA symbol Ade[6]) is a calcium, magnesium, arsenate with the chemical formula CaMgAsO
4
OH
, forming a solid solution series with the vanadium-bearing mineral gottlobite, where various transition metals substitute for magnesium and lead replaces calcium leading to a variety of similar minerals in the adelite - duftite group.

Aeschynites[edit | edit source]

Aeschynite has the chemical formula (Ce,Ca,Fe,Th)(Ti,Nb)
2
(O,OH)
6
.[15]

Here there are two oxygen groups:

  1. O, oxygenides, from 11.1 to 55.6 at % likely, and
  2. OH, hydroxides, from 55.6 to 11.1 at % likely.

Aeschynites-(Ce)[edit | edit source]

The IMA symbol is Aes-Ce.[6]

Chemical formula: (Ce,Ca,Fe,Th)(Ti,Nb)
2
(O,OH)
6
.

The "-(Ce)" means it has more cerium than the yttrium variety aeschynite-(Y). Its Mohs scale rating is 5–6.

Aeschynites-(Nd)[edit | edit source]

Aeschynite-(Nd) is a rare earth mineral of neodymium, cerium, calcium, thorium, titanium, niobium, oxygen, and hydrogen with formula: (Nd,Ce,Ca,Th)(Ti,Nb)
2
(O,OH)
6
. Its name comes from the Greek word for "shame". Its Mohs scale rating is 5 to 6. It is a member of the hydroxide minerals.

It was first reported for an occurrence in Bayan Obo Inner Mongolia in 1982. In that rare earth mining deposit it occurs in veins within metamorphosed dolomite and slate. It occurs associated with aegirine, riebeckite, barite, fluorite, albite, phlogopite and magnetite.[16] The IMA symbol is Aes-Nd.[6]

Aeschynites-(Y)[edit | edit source]

A fine, well-terminated, complete all-around aeschynite-(Y) crystal from Iveland, Norway. Credit: Robert M. Levinsky.{{free media}}

Aeschynite-(Y) (or Aeschinite-(Y), Aeschynite-(Yt), Blomstrandine, Priorite) is a rare earth mineral of yttrium, calcium, iron, thorium, titanium, niobium, oxygen, and hydrogen with formula: (Y,Ca,Fe,Th)(Ti,Nb)
2
(O,OH)
6
. Its name comes from the Greek word for "shame". Its Mohs scale rating is 5 to 6. The IMA symbol is Aes-Y.[6]

Afwillites[edit | edit source]

The clear to white small crystals on the rock are afwillite. Credit: Dave Dyet.{{free media}}

The chemical formula is Ca
3
(SiO
3
OH
)
2
·2H
2
O
. Afwillite (IMA symbol: Afw[6]) is a calcium hydroxide nesosilicate mineral that occurs as glassy, colorless to white prismatic monoclinic crystals, has a Mohs scale hardness between 3 and 4, occurs as an alteration mineral in contact metamorphism of limestone,[17] in association with apophyllite, natrolite, thaumasite, merwinite, spurrite, gehlenite, ettringite, portlandite, hillebrandite, foshagite, brucite and calcite.[17]

It was first described in 1925 for an occurrence in the Dutoitspan Mine, Kimberley, South Africa and was named for Alpheus Fuller Williams (1874–1953), a past official of the De Beers diamond company.[18]

Afwillite has had a couple of formulas:

  1. Ca
    3
    Si
    2
    O
    4
    (OH)
    6
    ,[15] and
  2. Ca
    3
    (HSiO
    4
    )
    2
    ·2H
    2
    O
    .[19]

Afwillite may form in fractured veins of the mineral spurrite. Jennite, afwillite, oyelite and calcite are all minerals that form in layers within spurrite veins. Afwillite, and calcite, may form from precipitated fluids. Jennite is actually an alteration of afwillite, but both formed from calcium silicates through hydration. Laboratory studies determined that afwillite forms at a temperature below 200 °C (392 °F), usually around 100 °C.[20] Afwillite and spurrite are formed through contact metamorphism of limestone.[21] Contact metamorphism is caused by the interaction of rock with heat and/or fluids from a nearby crystallizing silicate magma.[22]

Structurally, afwillite is a nesosilicate with isolated SiO4 tetrahedra.

Afwillite has two oxides:

  1. 2SiO4, Silicates, and
  2. 2H2O, oxidanes, with each having about 50 molecular %.

Calcium does not occur as native calcium. Here it links to the oxygens in the silicate tetrahedra and the oxidanes. Afwillite is 47.6 at % silicate and 28.6 at % oxidane.

Afwillite has a complex monoclinic structure, and the silicon tetrahedra in the crystal structure are held together by hydrogen bonds.[23] It has perfect cleavage]] parallel to its (101) and poor cleavage parallel to its (100) faces.[24] It is biaxial and its 2V angle, the measurement from one optical axis to the other optical axis, is 50 – 56 degrees. When viewed under crossed polarizers in a petrographic microscope, it displays first-order orange colors, giving a maximum birefringence of 0.0167 (determined by using the Michel- Levy chart). Afwillite is optically positive. Additionally, it has a prismatic crystal habit.[20] Under a microscope afwillite looks like wollastonite, which is in the same family as afwillite.

Afwillite is composed of double chains that consist of calcium and silicon polyhedral connected to each other by sharing corners and edges. This causes continuous sheets to form parallel to its miller index [-101] faces. The sheets are bonded together by hydrogen bonds and are all connected by Ca-Si-O bonds (Malik and Jeffery, 1976).[23] Each calcium atom is in 6-fold octahedral coordination with the oxygen, and the silicon is in 4-fold tetrahedral coordination around the oxygen. Around each silicon there is one OH group and there are three oxygens that neighbor them.[23] The silicon tetrahedra are arranged so that they share an edge with calcium(1), and silicon(2) shares edges with the calcium(2) and calcium(3) polyhedral.[23] The silicon tetrahedra are held together by the OH group and hydrogen bonding occurs between the hydrogen in the OH and the silicon tetrahedra. Hydrogen bonding is caused because the positive ion, hydrogen, is attracted to negatively charge ions which, in this case, are the silicon tetrahedra.[22]

Agardites[edit | edit source]

An example of agardite-(Ce) is in the form of pistachio-green acicular crystals on contrasting matrix. Credit: Robert M. Lavinsky.{{free media}}

Agradite has the chemical formula (REE,Ca)Cu
6
(AsO
4
)
3
(OH)
6
·3H
2
O
, a repeating unit.

Agardite is a mineral group consisting of agardite-(Y),[25][26] agardite-(Ce),[27] agardite-(Nd),[28] and agardite-(La).[29] They have been allocated the IMA symbols Agr-Y, Agr-Ce, Agr-Nd and Agr-La.[6] They comprise a group of minerals that are hydrous hydrated arsenates of rare-earth elements (REE) and copper, with the general chemical formula (REE,Ca)Cu
6
(AsO
4
)
3
(OH)
6
·3H
2
O
. Yttrium, cerium, neodymium, lanthanum, as well as trace to minor amounts of other REEs, are present in their structure. Agardite-(Y) is probably the most often found representative. They form needle-like yellow-green (variably hued) crystals in the hexagonal crystal system. Agardite minerals are a member of the mixite structure group, which has the general chemical formula Cu2+
6
A(TO
4
)
3
(OH)
6
·3H
2
O
, where A is a REE, Al, Ca, Pb, or Bi, and T is P or As. In addition to the four agardite minerals, the other members of the mixite mineral group are calciopetersite,[30] goudeyite,[31] mixite,[32] petersite-(Ce),[33] petersite-(Y),[34][26] plumboagardite,[35] and zálesíite.[36]

Agardite-(Y) from the Bou Skour mine in Djebel Sarhro, Morocco was the first of the agardite-group minerals to be characterized.[25] It was described by Dietrich in 1969 and was named after Jules Agard, a French geologist at the Bureau de Recherches Géologiques et Minières, Orléans, France.[37] Agardite-group minerals have subsequently been found in Germany,[38] Czech Republic,[39] Greece,[40] Italy,[41] Japan,[42] Namibia,[43] Poland,[44] Spain,[42] Switzerland,[45] the United Kingdom,[46] and the United States.[47]

Agrinierites[edit | edit source]

Agrinierite is from Margnac Mine, Compreignac, Haute-Vienne, Nouvelle-Aquitaine, France. Credit: Leon Hupperichs.{{free media}}

Agrinierite (K
2
(Ca,Sr)(UO
2
)
3
O
3
(OH)
2
·5H
2
O
)[48] is a mineral often found in the oxidation zone of uranium deposits. The 'IMA symbol is Agn.[6] It is named for Henry Agrinier (1928–1971), an engineer for the Commissariat à l'Énergie Atomique.

Chemical formula for Agrinierite is (K
2
,Ca,Sr)
U
3
O
10
·4(H
2
O
).[49][50]

Formula for Agrinierite is K
2
(Ca,Sr)[(UO
2
)
3
O
3
(OH)
2
]
2
·5H
2
O
.[51]

Aheylites[edit | edit source]

Translucent ~2 mm spheres of aheylite are perched on dark cassiterite, together with elongated quartz crystals. Credit: Robert M. Lavinsky.{{free media}}

Aheylite (International Mineralogical Association (IMA) symbol: Ahe[6]) is a rare phosphate mineral with formula (Fe2+
Zn)Al
6
[(OH)
4
(PO
4
)
2
]
2
·4(H
2
O
) that occurs as pale blue to pale green triclinic crystal masses,[52] the newest member of the turquoise group in 1984 by International Mineralogical Association Commission on New Minerals and Mineral Names.

The turquoise group has a basic formula of A
(0-1)
B
6
(PO
4
)
4−x
(PO
3
OH
)
x
(OH)
8
·4H
2
O
. This group contains six minerals: aheylite, planerite, turquoise, faustite, chalcosiderite, and an unnamed Fe2+
-Fe3+
analogue. Aheylite is distinguished in this group by having Fe2+
dominant in the A-site. The ideal aheylite has a formula of Fe2+
Al
6
(PO
4
)
4
(OH)
8
·4H
2
O
, a pale blue or green. With the turquoise family the blue color is said to come from the octahedral coordination of Cu2+
in the absence of Fe3+
.[53]

It was first described for an occurrence in the Huanuni mine, Huanuni, Oruro Department, Bolivia, and named for Allen V. Heyl (1918–2008), an economic geologist for the United States Geological Survey.[54] It was discovered by Eugene Foord and Joseph Taggart.[53]

In addition to the type locality in Bolivia it has been reported from the Bali Lo prospect in the Capricorn Range, Western Australia[52] and the Les Montmins Mine, Auvergne, France.[54] It is a turquoise group mineral and occurs as a late hydrothermal phase in a tin deposit associated with variscite, vivianite, wavellite, cassiterite, sphalerite, pyrite and quartz in the type locality.[52][55]

It is found as an isolated mass of hemispheres and spheres clumped together. It has a vitreous to dull luster. It has a hackly to splintery fracture and it has a brittle tenacity. The hardness is about 5-5.5, and the specific gravity is 2.84. As far as optical properties, it had thin flakes; ipale blue, green to blue-green color; it streaks white, and has a subvitreous luster.[53]

Ajoites[edit | edit source]

Bluish ajoite inclusion is in a colourless quartz crystal. Credit: Robert M. Lavinsky.{{free media}}
Ajoite is in quartz from Messina District, South Africa (size: 16.9 x 3.7 x 3 cm.) Credit: Robert M. Lavinsky.{{free media}}

Ajoite has the chemical formula (Na,K)Cu
7
AlSi
9
O
24
(OH)
6
·3H
2
O
,[56] and minor Mn, Fe and Ca are usually also present in the structure.[57] Ajoite is used as a minor ore of copper.

Ajoite (International Mineralogical Association (IMA) symbol Aj[6]) is a hydrated sodium potassium copper aluminium silicate hydroxide mineral.

Ajoite is a secondary mineral that forms from the oxidation of other secondary copper minerals in copper-rich base metal deposits in massive fracture coatings, in vein fillings, and in vugs. It may form from shattuckite and also it may be replaced by shattuckite.[57]

At the type locality it is associated with shattuckite, conichalcite, quartz, muscovite and pyrite.[58][56]

Ajoite is named after its type locality, the New Cornelia Mine in the Ajo District of Pima County, Arizona. Type specimen material is conserved at the National Museum of Natural History, Washington DC, USA, reference number 113220.

Other localities include Wickenburg and Maricopa County, Arizona, within the United States, and the Messina (Musina) District in South Africa. Quartz specimens from the defunct Messina Mines on the border between Zimbabwe and South Africa are well known for their inclusions of blue copper silicate minerals such as shattuckite, papagoite and ajoite,[59] but ajoite from American localities does not occur like this.

Akaganeites[edit | edit source]

A piece of the mineral akaganeite is in the exhibit of the "Earth and Man" Museum in Sofia, Bulgaria. Credit: Vassia Atanassova - Spiritia.{{free media}}

Akaganeites have the chemical formula Fe3+
O
(OH,Cl).

Akaganeite (International Mineralogical Association (IMA) symbol: Akg[6]), also written as the deprecated Akaganéite,[60] is a chloride-containing iron(III) oxide-hydroxide mineral, formed by the weathering of pyrrhotite (Fe
(1−x)
S
).

Akaganeite is often described as the β phase of anhydrous Iron(III) oxide-hydroxide (ferric oxyhydroxide) FeOOH, but some chloride (or fluoride) ions are normally included in the structure,[61] so a more accurate formula is FeO
0.833
(OH)
1.167
Cl
0.167
.[62] Nickel may substitute for iron, yielding the more general formula (Fe3+
,Ni2+
)
8
(OH,O)
16
Cl
1.25
[63]

Akaganeite has a metallic luster and a brownish yellow streak, crystal structure is monoclinic and similar to that of hollandite BaMn
8
O
16
, characterised by the presence of tunnels parallel to the c-axis of the tetragonal lattice. These tunnels are partially occupied by chloride anions that give to the crystal its structural stability.[62]

Occurrence: The mineral was discovered in the Akagane mine in Iwate, Japan, for which it is named. It was described by the Japanese mineralogist Matsuo Nambu in 1968,[64] but named as early as 1961.[65][66]

Akaganeite has also been found in widely dispersed locations around the world and in rocks from the Moon that were brought back during the Apollo Project. The occurrences in meteorites and the lunar sample are thought to have been produced by interaction with Earth's atmosphere. It has been detected on Mars through orbital imaging spectroscopy.[67]

Akrochordites[edit | edit source]

Bright green, vitreous, cluster of eveite (under 0.5 mm) and brown, subhedral akrochordite are in a contrasting, pink, granular carbonate matrix. Credit: Robert M. Lavinsky.{{free media}}

Akrochordites have the following formulae:

  1. Formula: (Mn2+
    ,Mg)
    5
    (AsO
    4
    )
    2
    (OH)
    4
    · 4H
    2
    O
    [68][69]
  2. Chemical formula: Mn2+
    4
    Mg(AsO
    4
    )
    2
    (OH)
    4
    ·4H
    2
    O
    .[70][71]

Environment: "A rare mineral in hausmannite ore from a metamorphosed Fe-Mn orebody (Långban, Sweden); in a metamorphosed stratiform zinc orebody (Sterling Hill, New Jersey, USA)."[71]

Akrochordite (International Mineralogical Association (IMA) symbol: Akr[6]) is a rare hydrated arsenate mineral that represents a small group of rare manganese (Mn) arsenates and, similarly to most other Mn-bearing arsenates, possess pinkish colour, typically associated with metamorphic Mn deposits.[72][73]

Aksaites[edit | edit source]

Aksaites have the formula Mg[B
6
O
7
(OH)
6
] · 2H
2
O
,[74] IMA symbol is Aks, IMA formula: MgB
6
O
7
(OH)
6
· 2H
2
O
.[6]

Aksaite is orthorhombic.[75]

"According to the results of the structural analysis, the largest thermal motion is shown by the water molecule, O(14), which is only linked to the Mg atom and to O(13") through a hydrogen bond. The thermal amplitude of two of the three triangular hydroxyls, O(11) and O(13), involved in a bond with boron as well as in two hydrogen bonds, is rather large. Much smaller is the displacement of the O(12) hydroxyl which is also participating to a bond with magnesium. It is also easy to understand the slight thermal motion of the water molecule O(15), which is involved in a bond with magnesium and in three hydrogen bonds as well."[75]

Ashoverites[edit | edit source]

Ashoverite from Milltown Quarry, Milltown, Ashover, North East Derbyshire District, Derbyshire, England, UK. Credit: Steve Rust.{{fairuse}}

Ashoverite is one of three polymorphs of zinc hydroxide, Zn(OH)
2
, a rare mineral first found in a limestone quarry near Ashover, Derbyshire, England, in 1988.[76]

Ashoverite is trimorphous with sweetite and wülfingite.[77]

Ashoverite occurs in "a vein in a limestone quarry, on fluorite associated with the polymorphs, sweetite and wulfingite."[78]

Ashoverite colourless-white tabular crystals are shown in a iron-stained fluorite cavity in the image on the right.

Axinites[edit | edit source]

Axinite is a calcium aluminum borosilicate mineral that can occur in violet. Credit: Didier Descouens.

Axinite-(Mg) or magnesioaxinite, Ca2MgAl2BOSi4O15(OH) magnesium rich, can be pale blue to pale violet[79]

Azurites[edit | edit source]

Azurite is from the Burra Mine, South Australia. Credit: JJ Harrison.{{free media}}
Chemical structure is of azurite. Color code: red = O, green = Cu, gray = C, white = H). Credit: Smokefoot.{{free media}}

Azurite is a soft, deep-blue copper mineral produced by weathering of copper ore deposits.

During the early 19th century, it was also known as chessylite, after the type locality at Chessy-les-Mines near Lyon, France.[80] The mineral, a basic carbonate with the chemical formula Cu
3
(CO
3
)
2
(OH)
2
, has been known since ancient times, and was mentioned in Pliny the Elder's Natural History under the Greek name kuanos (κυανός: "deep blue," root of English cyan) and the Latin name caeruleum.[81] Since antiquity, azurite's exceptionally deep and clear blue has been associated with low-humidity desert and winter skies. The modern English name of the mineral reflects this association, since both azurite and azure are derived via Arabic from the Persian lazhward (لاژورد), an area known for its deposits of another deep-blue stone, lapis lazuli ("stone of azure").

Bayerites[edit | edit source]

Idealized structure of gibbsite is projected on (001), showing geometric relations of the cells of gibbsite (solid lines), bayerite (dashed lines), doyleite (dotted lines) and nordstrandite. Credit: George Y. Chao and Judith Baker, Ann P. Sabina and Andrew C. Roberts.

Bayerite is a polymorph of gibbsite and has the same chemical formula. Part of the challenge of determining the unique structure of bayerite versus gibbsite is that bayerite appears to transform to gibbsite under certain circumstances. The structures may also interleave. The other two polymorphs: nordstrandite and doyleite, are also variations with possible interleaving.

Early structural determinations using powder diffraction studies appeared contradicting.

The first structural study (1942) found bayerite to be hexagonal with two formula units (Z) per unit cell.[82] The lattice parameters were a=5.01 Å and c=4.76 Å.[82]

A second study (1951) found bayerite to be monoclinic.[83]

A third study (1958) found bayerite to be hexagonal with a=5.047 Å and c=4.730 Å with Z=2.[84]

Doyleite "the mineral from Mont St. Hilaire [is] triclinic, space group P1̅ from morphology, a 5.002(1), b 5.175(1), c 4.980(2) , α 97.50(1), β 118.60(1), γ 104.74(1)°, Z = 2."[85]

Bayerite has a monoclinic structure and lattice parameters of a=5.062(1) Å, b=8.671(2) Å, c=4.713(1) Å, β =90.27(3)° with space group P21/a.[85]

"The primitive P1̅ unit cell of nordstrandite was confirmed to contain four formula units, unlike doyleite (Z = 2). The layered structures of nordstrandite and doyleite were shown to be closely related to that of bayerite, differing from one another by the interlayer shift vectors only."[86]

As of 2014, bayerite has the monoclinic (P21/m) (or brucite) structure.[87]

In the diagram on the right, an idealized "structure of gibbsite is projected on (001), showing geometric relations of the cells of gibbsite (solid lines), bayerite (dashed lines), doyleite (dotted lines) and nordstrandite. [Subscripts are] g for gibbsite, d for doyleite and n for nordstrandite. The oxygen atoms are at heights of 0.11 (shaded large circles) and -0.11 (unshaded)."[85]

Boehmites[edit | edit source]

Böhmite and Natrolite is from Sagåsen (Strandåsen), Mørje, Porsgrunn, Telemark, Norway (Field of view 10 mm). Credit: Leon Hupperichs.{{free media}}

Boehmite or böhmite is an aluminium oxide hydroxide (γ-AlO(OH)) mineral, a component of the aluminium ore bauxite. It is dimorphous with diaspore.

Boehmite occurs in tropical laterites and bauxites developed on alumino-silicate bedrock, occurs as a hydrothermal alteration product of corundum and nepheline, with kaolinite, gibbsite and diaspore in bauxite deposits; and with nepheline, gibbsite, diaspore, natrolite and analcime in nepheline pegmatites.[88]

Brucites[edit | edit source]

This brucite is from the Palabora mine, Loolekop, Phalaborwa, Limpopo Province, South Africa. Credit: Robert Matthew Lavinsky{{free media}}

Brucite is the mineral form of magnesium hydroxide, with the chemical formula Mg(OH)
2
. It is a common alteration product of periclase in marble; a low-temperature hydrothermal vein mineral in metamorphosed limestones and chlorite schists; and formed during serpentinization of dunites. Brucite is often found in association with serpentine], calcite, aragonite, dolomite, magnesite, hydromagnesite, artinite, talc and chrysotile.

It adopts a layered CdI2-like structure with hydrogen-bonds between the layers.[89]

Calumetites[edit | edit source]

This specimen of calumetite is from the Akmeek No. 2 Mine in Keweenaw County, Michigan, held at the A. E. Seaman Mineral Museum. Credit: Chris857.{{free media}}

Calumetite has the chemical formula Cu(OH,Cl)2·2H2O.[15]

Carrboydites[edit | edit source]

Green globular aggregates of the nickel sulphate mineral carrboydite from the type locality. Credit: David Hospital.{{free media}}

Carrboydite has the formula: (Ni
(1-x)
Al
x
)(SO
4
)
(x/2)
(OH)
2
·nH
2
O
, where (x < 0.5, n > 3x/2), is a member of the Glaucocerinite Group > Hydrotalcite Supergroup, in the Hexagonal Crystal System, named for the Carr Boyd nickel mine, Australia, the type locality.[90]

Carrboydite has the Chemical Formula: (Ni,Cu)
14
Al
9
(SO
4
,CO
3
)(OH)
43
•7(H
2
O
).[91] The Empirical Formula is Ni
10
Cu
4
Al
9
(SO
4
)
4
(CO
3
)
2
(OH)
43
•7(H
2
O
).[91]

"As part of the recent re-evaluation of the nomenclature of the hydrotalcite supergroup (Mills et al., 2012), carrboydite was identified as a questionable species which needs further investigation."[90]

Environment: "Surface material at a nickel mine."[90]

Diaspores[edit | edit source]

Doyleites[edit | edit source]

Gibbsites[edit | edit source]

Gibbsite from the Xianghualing Mine (Hsianghualing Mine), Xianghualing Sn-polymetallic ore field, Linwu County, Chenzhou Prefecture, Hunan Province, China. Credit: Robert M. Lavinsky.{{free media}}

Gibbsite, Al(OH)
3
, is one of the mineral forms of aluminium hydroxide, often designated as γ-Al(OH)
3
[92] (but sometimes as α-Al(OH)3.[93]). It is also sometimes called hydrargillite (or hydrargyllite). Doyleite and nordstrandite are triclinic forms.[92]

The structure of gibbsite is analogous to the basic structure of the micas. The basic structure forms stacked sheets of linked octahedra. Each octahedron is composed of an aluminium ion bonded to six hydroxide groups, and each hydroxide group is shared by two aluminium octahedra.[94]

Gibbsite is often found as a part of the structure of other minerals. The neutral aluminium hydroxide sheets are found sandwiched between silicate sheets in important clay groups: the illite, kaolinite, and montmorillonite/smectite groups. The individual aluminium hydroxide layers are identical to the individual layers of gibbsite and are referred to as the gibbsite layers.[95]

Gillardites[edit | edit source]

Gillardite is an extremely rare copper nickel chlorine halide, found only at this locality to date. Credit: Robert M. Lavinsky.{{free media}}

Gillardite from 132 North Ni Mine, Widgiemooltha, Coolgardie Shire, Western Australia, Australia has the chemical formula Cu
3
Ni(OH)
6
Cl
2
[96]

This is a very rare attractive specimen on the right that is just loaded with crystalline gillardite, perched on lighter-green gaspeite. This mineral seldom crystallizes and although small, these crystals are discrete and eye-visible.

Glaucophanes[edit | edit source]

This is a specimen of glaucophane with fuchsite. Credit: Didier Descouens.

Often a mineral appears blue due to the presence of copper or sulfur. Glaucophane is a blue silicate that owes its color to its characteristic formation.

Glaucophane is a mineral belonging to the amphibole group, chemical formula Na
2
Mg
3
Al
2
Si
8
O
22
(OH)
2
. The blue color is very diagnostic for this species. It, along with the closely related mineral riebeckite are the only common amphibole minerals that are typically blue. Glaucophane forms in metamorphic rocks that are either particularly rich in sodium or that have experienced low temperature-high pressure metamorphism such as would occur along a subduction zone. This material has undergone intense pressure and moderate heat as it was subducted downward toward the mantle. It is glaucophane's color that gives the blueschist facies its name. Glaucophane is also found in eclogites that have undergone retrograde metamorphism.[97]

Glaukosphaerites[edit | edit source]

Glaukosphaerite is from Kasompi Mine (Menda Mine; Kasompi Hill), Swambo, Central area, Katanga Copper Crescent, Katanga (Shaba), Democratic Republic of Congo (Zaïre). Credit: Robert M. Lavinsky.{{free media}}

Glaukosphaerites have the CNMMN/CNMNC approved formula: CuNi(CO
3
)(OH)
2
[98] and the Strunz formula: (Cu,Ni)2[(OH)2|CO3],[99] or (Cu,Ni)
2
(CO
3
)(OH)
2
.[100]

It is a member of the Rosasite Group.[100]

Associated Minerals at Type Locality: Goethite, Quartz, Paratacamite, Gypsum, Magnesite, Malachite, and Clay.[100]

Goethites[edit | edit source]

Hydrohonessites[edit | edit source]

Outstanding green sharp isolated hydrohonessite crystal on millerite from this Italian locality (Groppallo, Piacenza Province, Emilia Romagna, Italy) in a contrasting matrix. Credit: David Hospital.{{free media}}

In the image on the right, hydrohonessite was riginally described as jamborite, now most green coatings on millerite like this have been shown to be hydrohonessite per David Hospital.

Hydrohonessite has the formula: (Ni
1-x
Fe3+
x
)(OH)
2
(SO
4
)
x/2
· nH
2
O
(x > 0.5, n > ​3x2.[101]

"May convert readily into honessite, depending on humidity and temperature. Appears to be stable between pH 6 and 7."[101]

General Appearance of Type Material: Thin surface encrustation of tiny hexagonal crystals on botryoidal quartz and magnesite in a fracture in supergene Ni-Fe sulphides.[101]

Associated Minerals at Type Locality: Quartz, Magnesite, Violarite, Pyrite, Gaspéite, Goethite, Pecoraite and Gypsum.[101]

"A precipitate corresponding to hydrohonessite was obtained by slowly adding an aqueous 0.1 M ferrous sulphate solution to a 0.1 M nickel sulphate solution. The pH of the solution was maintained between 6.0 and 6.5 by the addition of 0.01 M sodium carbonate. Above pH 7.5, Ni(OH)
2
is precipitated, and below pH 6, FeOOH. The oxidation of the iron and precipitation of the hydrohonessite is slow, so care must be taken that the pH does not drop too low during the approximately 24 hours that the precipitation requires. After drying at 25°C, the precipitate gives a diffuse X-ray powder pattern similar to that of hydrohonessite. Chemical analysis of the precipitate confirmed that the composition is close to that of hydrohonessite. The infra-red spectrum of the synthetic hydrohonessite [...] is similar to that of honessite (Bish and Livingstone, 1981), and is characterized by strong absorptions due to H
2
O
and SO
4
. The synthetic hydrohonessite dehydrates slowly at 25°C, and after ten days it gives a diffuse X-ray diffraction pattern of four lines which correspond to the strongest lines of the honessite diffraction pattern (Bish and Livingstone, 1981), i.e. with a basal spacing in the neighbourhood of 9 Å; the conversion can also be achieved more rapidly by heating the synthetic hydrohonessite at 110°C. The natural hydrohonessite is more stable than its synthetic equivalent, since it retains its integrity at 110°C, and dehydration requires a temperature between 150 and 170°C. The dehydration experiments indicate that hydrohonessite is the hydrated equivalent of honessite."[102]

Kaolinites[edit | edit source]

Kaolinite is from Twiggs County, Georgia, USA. Credit: James St. John.{{free media}}

Kaolinite has the chemical formula Al
2
Si
2
O
5
(OH)
4
.

Kaolinite is a clay mineral, a layered silicate mineral, with one tetrahedral sheet of silica (SiO
4
) linked through oxygen atoms to one octahedral sheet of alumina (AlO
6
) octahedra.[103] Rocks that are rich in kaolinite are known as kaolin or porcelain (china) clay.[104]

The chemical formula for kaolinite as used in mineralogy is Al
2
Si
2
O
5
(OH)
4
,[105] however, in ceramics applications the formula is typically written in terms of oxides, thus the formula for kaolinite is Al
2
O
3
*2SiO
2
*2H
2
O
.[106]

As the most numerous element is oxygen at 9 for 52.9 at %, kaolin is an oxide.

Kambaldaites[edit | edit source]

Kambaldaite is from Otter Shoot Nickel mine, Otter Juan mine, Kambalda Nickel deposit, Kambalda, Coolgardie Shire, Western Australia, Australia. Credit: Leon Hupperichs.{{free media}}

Kambaldaites have the formula: NaNi
4
(CO
3
)
3
(OH)
3
· 3H
2
O
.[107]

General Appearance of Type Material: Cryptocrystalline veins, layers and concretionary growths up to about 2 mm thick, commonly intergrown with gaspeite, also as encrustations of tiny hexagonal prisms.[107]

Geological Setting of Type Material: Nickel sulfide deposit, as a secondary mineral that has been precipitated on fracture surfaces in oxidizing Ni-Fe sulfide ore.[107]

"The primary sulfides, which occur as assemblages of pentlandite-pyrrhotite-pyrite and pentlandite-millerite-pyrite, have been altered to supergene assemblages consisting largely of violarite and pyrite, which have decomposed on further oxidation to a goethitic residue in which the secondary nickel minerals have been deposited."[108]

"The samples in which the kambaldaite was found are from a depth of about 20 meters, and consist largely of goethite with some reevesite and residual pyrite. The kambaldaite, together with gaspeite and some aragonite, occurs on fracture surfaces in the goethite. The kambaldaite occurs in a variety of types: massive, crystalline, nodular and chalky."[108]

Lazurites[edit | edit source]

Lazurite is a deep blue tectosilicate. Credit: Didier Descouens.{{free media}}

Lazurite is a tectosilicate mineral with sulfate, sulfur and chloride with formula: (Na,Ca)
8
[(S,Cl,SO
4
,OH)
2
(Al
6
Si
6
O
24
)
]
. It is a feldspathoid and a member of the sodalite group. The colour is due to the presence of S3- anions. Lazurite is a product of contact metamorphism of limestone.

Lepidolites[edit | edit source]

Lavender lepidolite has been found in the Himalaya Mine, Mesa Grande District, San Diego County, California, USA. Credit: Rob Lavinsky.{{free media}}

Lepidolite (KLi
2
Al(Al,Si)
3
O
10
(F,OH)
2
is a lilac-gray or rose-colored member of the mica group that is a secondary source of lithium, a phyllosilicate mineral[109] and a member of the polylithionite-trilithionite series.[110]

It is associated with other lithium-bearing minerals like spodumene in pegmatite bodies. It is one of the major sources of the rare alkali metals rubidium and caesium.[111]

It occurs in granite pegmatites, in some high-temperature quartz veins, greisens and granites. Associated minerals include quartz, feldspar, spodumene, amblygonite, tourmaline, columbite, cassiterite, topaz and beryl.

Libethenites[edit | edit source]

Libethenite specimen is from Kambove, Central area, Katanga Copper Crescent, Katanga (Shaba), Democratic Republic of Congo (Zaïre). Credit: Robert M. Lavinsky.{{free media}}
Detail is of gemmy, emerald-green, orthorhombic libethenite microcrystals on malachite, from the type locality, Ľubietová, Slovakia. Credit: Robert M. Lavinsky.{{free media}}
Libethenite is from Podlipa and Reinera Mines, Ľubietová (Libetbánya; Libethen) ore belt, Western Slovenské Rudohorie Mts, Banská Bystrica Region, Slovakia. Credit: Robert M. Lavinsky.{{free media}}

Libethenite has the chemical formula Cu
2
PO
4
OH
, is a rare copper phosphate hydroxide mineral, that forms striking, dark green orthorhombic crystals, discovered in 1823 in Ľubietová, Slovakia, is named after the German name of that locality (Libethen).[112][113] Libethenite has also been found in the Miguel Vacas Mine, Conceição, Vila Viçosa, Évora District, Portugal, and in Tier des Carrières, Cahai, Vielsaim, Stavelot Massif, Luxembourg Province, Belgium.[113]

Libethenite almost always takes the form of dark-green orthorhombic crystals,[112][113] often found in clusters with other libethenite crystals.

Libethenite is found in the oxidized zone of copper ore deposits,[113] is most often formed from the weathering of phosphate rocks such as apatite, monazite, and xenotime.[113] There have been no confirmed findings of primary libethenite, although a probable case has been reported.[113]

Linarites[edit | edit source]

This specimen of a copper mineral called linarite contains unusual large crystals. Credit: Wynne Parry.

Linarite is an monoclinic azure blue mineral with the chemical formula of PbCuSO4(OH)2.[15]

Malachites[edit | edit source]

This malachite is from the Democratic Republic of the Congo. Credit: JJ Harrison.{{free media}}
Malachite is a mineral occurring on Earth, like many greens, is colored by the presence of copper, specifically by basic copper(II) carbonate.[114] Credit: Rob Lavinsky.{{free media}}

Malachite is a mineral that occurs in rocks at or near the interface between Earth's atmosphere and crust.

Malachite is a copper carbonate hydroxide mineral, with the chemical formula Cu
2
CO
3
(OH)
2
, which is 20 at % copper, 10 at % carbon, 20 at % hydrogen, 50 at % oxygen, 20 molecular % carbonate and 40 molecular % hydroxide.

This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses, in fractures and deep, underground spaces, where the water table and hydrothermal fluids provide the means for chemical precipitation. Individual crystals are rare, but occur as slender to acicular prisms. Pseudomorphs after more tabular or blocky azurite crystals also occur.[115]

Manganites[edit | edit source]

Metavauxites[edit | edit source]

Metavauxite is from Siglo Veinte Mine. Credit: Robert M. Lavinsky.{{free media}}

"More like akrochordite is metavauxite (R = 0.097), which is [Fe(H
2
O
)2+
6]
[Al
2
(OH)
2
(H
2
O
)
2
(PO
4
)
2
]2−
(Baur and Rama Rao, 1967), in that it has insular octahedra alternating with octahedral-tetrahedral sheets separated by the {100} plane. The plane is penetrated by three different hydrogen bonds that are accepted by O(4) of the terminal[PO
4
] tetrahedron of the sheets: OW(7)...O(4) 2.58,OW(7')...O(4) 2.64,and OW(8)...O(4) 2.67 Å. The remaining P-O(4) distance is about the same as the polyhedral average."[69]

Metavauxite in the image on the right is from Siglo Veinte Mine (Siglo XX Mine; Llallagua Mine; Catavi), Llallagua, Rafael Bustillo Province, Potosí Department, Bolivia.

Microlites[edit | edit source]

The image shows pale-yellow microlite on lepidolite. Credit: Rob Lavinsky.{{free media}}

Microlite is composed of sodium calcium tantalum oxide with a small amount of fluorine (Na,Ca)
2
Ta
2
O
6
(O,OH,F)
. Microlite is a mineral in the pyrochlore group that occurs in pegmatites and constitutes an ore of tantalum. It has a Mohs hardness of 5.5 and a variable specific gravity of 4.2 to 6.4. It occurs as disseminated microscopic subtranslucent to opaque octahedral crystals with a refractive index of 2.0 to 2.2. Microlite is also called djalmaite. Microlite occurs as a primary mineral in lithium-bearing granite pegmatites, and in miarolitic cavities in granites.

Népouites[edit | edit source]

Népouite is from Népoui Mine, North Province, New Caledonia. Credit: Didier Descouens.{{free media}}

Népouite is a rare nickel silicate mineral which has the apple green colour typical of such compounds. The ideal formula is Ni3(Si2O5)(OH)4, but most specimens contain some magnesium, and (Ni,Mg)3(Si2O5)(OH)4 is more realistic. There is a similar mineral called lizardite (named after the Lizard Complex in Cornwall, England) in which all of the nickel is replaced by magnesium, formula Mg3(Si2O5)(OH)4.[116] These two minerals form a series; intermediate compositions are possible, with varying proportions of nickel to magnesium.[117]

Nordstrandites[edit | edit source]

Nullaginites[edit | edit source]

Outstanding green crystals of the very rare nickel mineral nullaginite from the famous mine of 132 North mine (Widgiemooltha, Western Australia, Australia), famous for its paragenesis of nickel minerals. Credit: David Hospital.{{free media}}

"In nature there exists [the] hydroxy nickel carbonate [mineral] nullaginite Ni
2
(CO
3
)
(OH)
2
1-3 [...] Nullaginite is monoclinic with point group 2/m and is a member of the rosasite mineral group. Nullaginite is formed in the oxidised zone of nickel rich hydrothermal ore deposits."[118]

Olivenites[edit | edit source]

Olivenite is from Špania Dolina, Slovakia. Credit: .{{free media}}
Olivenite is from Mammoth Mine, Tintic, Utah. Credit: Andrew Silver.{{fairuse}}

Olivenite is a copper arsenate mineral has the chemical formula Cu
2
AsO
4
OH
crystallizes in the monoclinic system (pseudo-orthorhombic),[119] is a mineral of secondary origin, a result of the oxidation of copper ores and arsenopyrite.

The mineral was formerly found in some abundance, associated with limonite and quartz, in the upper workings in the copper mines of the St Day district in Cornwall; also near Redruth, and in the Tintic Mining District in Utah.

The arsenic of olivenite is sometimes partly replaced by a small amount of phosphorus, and in the species libethenite we have the corresponding copper phosphate Cu
2
PO
4
OH
, found as small dark green crystals resembling olivenite at Ľubietová in the Slovak Republic, and in small amount also in Cornwall. Other members of this isomorphous group of minerals are adamite, Zn
2
AsO
4
OH
, and eveite, Mn
2
AsO
4
OH
.

Otwayites[edit | edit source]

Otwayite is from the type locality in Otway Nickel deposit. Credit: David Hospital.{{free media}}

Otwayite has the chemical formula Ni
2
CO
3
(OH)
2
.[118]

Otwayite has the formula: Ni
2
CO
3
(OH)
2
· H
2
O
.[120]

Geological Setting of Type Material: Narrow veinlets to 1 mm in width, probably late-stage fracture filling, transecting nickeloan serpentine, millerite, polydymite, and apatite.[120]

Otwayite is associated with Widgiemoolthalite.[120]

Occurrence: Otwayite is found in association with nullaginite and hellyerite in the Otway nickel deposit, is found in association with theoprastite, hellyerite, gaspeite and a suite of other nickel carbonate minerals in the Lord Brassey Mine, Tasmania, in association with gaspeite, hellyerite and kambaldaite in the Widgie Townsite nickel gossan, Widgiemooltha, Western Australia, and reported from the Pafuri nickel deposit, South Africa.[121]

It was first described in 1977 from the Otway Nickel Deposit, Nullagine, Pilbara Craton, Western Australia and named for Australian prospector Charles Albert Otway (born 1922).[122]

Paratacamites[edit | edit source]

Paratacamite is from the Levant Mine, Trewellard, Botallack - Pendeen Area, St Just District, Cornwall, England, UK. Credit: Robert M. Lavinsky{{free media}}

Paratacamite has the chemical formula Cu
3
(Cu,Zn)(OH)
6
Cl
2
.[123]

A very rich specimen of microcrystalline, brilliant green paratacamite crystals - exceedingly rich from the locality. Ex. Richard Barstow Collection.

Paravauxites[edit | edit source]

Paravauxite is from Siglo Veinte Mine (Siglo XX Mine; Llallagua Mine; Catavi), Llallagua, Rafael Bustillo Province, Potosí Department, Bolivia. Credit: Robert M. Lavinsky.{{free media}}

Paravauxites have the formula Fe2+
Al
2
(PO
4
)
2
(OH)
2
· 8H
2
O
.[124]

Paravauxite is a rare mineral that was named in 1922, a portmanteau word made by blending the Greek word for near (παρα, meaning para) and vauxite due to the chemical relationship to vauxite, approved by the International Mineralogical Association (IMA), and was first described in 1959, grandfathered, meaning it is probably to remain a species.[124]

It is a member of the laueite supergroup, and the laueite group within said supergroup, a metavauxite triclinic dimorph that can form in complex granitic pegmatites, and in hydrothermal tin veins. It forms thick tabular crystals on {010}, and short prismatic ones on [001], but numerous forms might be exhibited. Forms aggregates that are subparallel to radial. The mineral is colorless in transmitted light.[124] It mainly consists of oxygen (60.26%), but contains phosphorus (12.96%), iron (11.69%), aluminum (11.29%) and hydrogen (3.80%) as well. It doesn't show any radioactive properties whatsoever.[125] It occurs in tin mines. Paravauxite has a vitreous luster, with one exception on b(100), where it is pearly. It grows in small crystals, which's size can reach up to 5×2×1.5 mm. Crystals are somewhat flattened parallel to b(100). Even with atmospheric humidity, paravauxite's hydrogen dioxide content varies considerably. The mineral's formula is complex, that's why it's really unlikely that it gets simplified by further analyses. There's only one occurrence where vauxite and paravauxite are seen together in one specimen. It's a small, cavernous, mass of druzy-green wavellite. It has blue vauxite in small radial aggregates, and a singular colorless paravauxite. One of blue vauxite's radial aggregates has this crystal implanted on top.[126]

Other than vauxite and metavauxite, it is also associated with wavellite, but rarely occurs on the latter, the type locality of Llallagua, Bolivia.[125] It can also be found in Germany, Mexico, the United States, Portugal, Sweden, with a couple of other countries.[127]

"Paravauxite can be found in association with vauxite, metavauxite, wavellite, sigloite, crandallite, childrenite, and quartz."[128]

Pecoraites[edit | edit source]

A small sample of Pecoraite associated with the ultramafic rocks in northern Vermont. Credit: John Mark Brigham.{{free media}}

Pecoraite is a nickel phyllosilicate[129] mineral and a member of the Serpentine Subgroup > Kaolinite-Serpentine Group, named after geologist William Thomas Pecora, is monoclinic and has a chemical composition of Ni
3
(Si
2
O
5
)(OH)
4
.[130]

Common Impurities: Al, Fe, Mg, Ca, H
2
O
.[130]

Geological Setting of Type Material: Weathered meteorite.[130]

Geological setting: Shears in ultramafic rocks, weathering product of millerite in geodes.[130]

Pecoriate is typically a green, lime green, or bluegreen mineral with a waxy, or earthy luster and a mohs hardness of 2.5.[129]

Morphology: curved plates, spirals and tubes, granular and massive.[130]

Pectolites[edit | edit source]

Pectolite is from the Millington Quarry (Morris County Crushed Stone County Quarry; Tilcon Quarry), Bernards Township, Somerset County, New Jersey, USA Credit: Robert M. Lavinsky.{{free media}}
Larimar is a rare blue variety of the silicate mineral pectolite found only in the Dominican Republic, in the Caribbean. Credit: Vassil.{{free media}}

Pectolite is a white to gray mineral, NaCa
2
Si
3
O
8
(OH), sodium calcium hydroxide inosilicate that crystallizes in the triclinic system typically occurring in radiated or fibrous crystalline masses, has a Mohs hardness of 4.5 to 5 and a specific gravity of 2.7 to 2.9. The gemstone variety, larimar, is a pale to sky blue.

Occurrence: It was first described in 1828 at Mt. Baldo, Trento Province, Italy, and named from the Greek pektos – "compacted" and lithos – "stone".[131][132]

Occurrence: as a primary mineral in nepheline syenites, within hydrothermal cavities in basalts and diabase and in serpentinites in association with zeolites, datolite, prehnite, calcite and serpentine. It is found in a wide variety of worldwide locations.

Pectolite is found in many locations, but larimar has a unique volcanic blue coloration, which is the result of copper substitution for calcium.[133]

Miocene volcanic rocks, andesites and basalts, erupted within the limestones of the south coast of the island, contained cavities or vugs which were later filled with a variety of minerals, including the blue pectolite, which are a secondary occurrence within the volcanic flows, dikes, and plugs, which erode, the pectolite fillings are carried down the slope to end up in the alluvium and the beach gravels, and the Bahoruco River carried the pectolite-bearing sediments to the sea.[134]

Larimar is a copper substituted for calcium NaCu
2
Si
3
O
8
(OH) pectolite, a rare blue variety of the silicate mineral pectolite found only in the Dominican Republic, in the Caribbean]]. Its coloration varies from white, light-blue, green-blue to deep blue.[134]

Portlandites[edit | edit source]

Portlandite and ettringite sample is from the Ettringer Feld, Kro. Mayen, Eifel, Germany. Credit: Ra'ike.{{free media}}

Portlandite is a hydroxide-bearing mineral typically included in the oxide mineral class, the naturally occurring form of calcium hydroxide Ca(OH)
2
and the calcium analogue of brucite Mg(OH)
2
.

Portlandite occurs in a variety of environments. At the type location in Northern Ireland it occurs as an alteration of calc–silicate rocks by contact metamorphism of larnite–spurrite. as fumarole deposits in the Vesuvius area, in Jebel Awq, Oman, it occurs as precipitates from an alkaline spring emanating from ultramafic bedrock, in the Chelyabinsk coal basin of Russia it is produced by combustion of coal seams and similarly by spontaneous combustion of bitumen in the Hatrurim Formation of the Negev desert in Israel and the Maqarin area, Jordan.[135] It also occurs in the manganese mining area of Kuruman, Cape Province, South Africa in the Kalahari Desert where it occurs as large crystals and masses.[136][135]

It occurs in association with afwillite, calcite, larnite, spurrite, halite, brownmillerite, hydrocalumite, mayenite and ettringite.[135]

It was first described in 1933 for an occurrence at Scawt Hill, Larne, County Antrim, Northern Ireland. It was named portlandite because the chemical calcium hydroxide is a common hydrolysis product of Portland cement.[136][135]

Romanèchites[edit | edit source]

Satterlyites[edit | edit source]

This Satterlyite sample is from the Rapid Creek area of northern Yukon, Canada. Credit: Chris857.

Satterlyite is a hydroxyl bearing iron phosphate mineral. The mineral can be found in phosphatic shales. Satterlyite is part of the phosphate mineral group. Satterlyite is a transparent, light brown to light yellow mineral. Satterlyite has a formula of (Fe2+,Mg,Fe3+)2(PO4)(OH). Satterlyite occurs in nodules in shale in the Big Fish River (Mandarino, 1978). These nodules were about 10 cm in diameter, some would consist of satterlyite only and others would show satterlyite with quartz, pyrite, wolfeite or maricite.

Holtedahlite, a mineral that was found in Tingelstadtjern quarry in Norway, with the formula (Mg12PO4)5(PO3OH,CO3)(OH,O)6 is isostructural with satterlyite (Raade, 1979). Infrared absorption powder spectra show that satterlyite is different than natural haltedahlite in that there is no carbonate for phosphate substitution (Kolitsch, 2002). Satterlyite is also structurally related to phosphoellenbergerite, a mineral that was discovered in Modum, Norway; near San Giocomo Vallone Di Gilba, in Western Alps of Italy (Palache, 1951); the minerals formula is Mg14(PO4)5(PO3OH)2(OH)6 (Kolitsch, 2002).

Spertiniites[edit | edit source]

Spertiniite is from Dzhezkazgan Mine (Zhezkazgan Mine), Dzhezkazgan, Zhezqazghan Oblysy (Dzezkazgan Oblast'; Dzhezkazgan Oblast'; Djezkazgan Oblast'; Jezkazgan Oblast'), Kazakhstan. Credit: Leon Hupperichs.{{free media}}
Crystal structure is of Copper(II) hydroxide. Credit: Orci{{free media}}

The mineral of the formula Cu(OH)
2
is called spertiniite.

Copper(II) hydroxide is rarely found as an uncombined mineral because it slowly reacts with carbon dioxide from the atmosphere to form a basic copper(II) carbonate. Thus copper slowly acquires a dull green coating in moist air by the reaction:

2Cu(OH)
2
+ CO
2
Cu
2
CO
3
(OH)
2
+ H
2
O

The green material is in principle a 1:1 mole mixture of Cu(OH)
2
and CuCO
3
.[137]

Stevensites[edit | edit source]

Stevensite has the chemical formula (Ca,Na)
x
Mg
3-x
Si
4
O
10
(OH)
2
and crystallizes in the Monoclinic system.

Sweetites[edit | edit source]

Sweetite is from Milltown Quarry, Milltown, Ashover, North East Derbyshire District, Derbyshire, England, UK. Credit: Steve Rust.{{fairuse}}

Sweetite has a general formula of Zn(OH)
2
.[138] The name is given after a curator of mineral department of The British Museum, Jessie May Sweet (1901–1979).[139] It occurs in an oxidized vein in limestone bedrock with galena, ashoverite, wülfingite, anglesite, cerussite, hydrocerussite, litharge, fluorite, palygorskite and calcite.[140]

Sweetite is tetragonal, which means crystallographically it contains one axis of unequal length and two axes of equal length. The angles between three of the axes are all 90°. It belongs to the space group 4/m. Some crystals show evidence of a basal plane and a few are tabular.[141] In terms of its optical properties, sweetite has two indices of refraction, 1.635 along the ordinary ray and 1.628 along the extraordinary ray.[139] The index of refraction is the velocity of light in a vacuum divided by the velocity of light in medium. It also has the birefringence of 0.007.[142] The birefringence means the decomposition of light into two rays when passing through a mineral. Sweetite is 1.64 - 1.65 in relief, which is medium to high in intensity and means a measure of the relative difference between the index of refraction of a mineral and its surrounding medium.[138]

Sweetite is mostly found from a limestone quarry 200–300 m northwest of Milltown, near Ashover, Derbyshire, England.[140]

Turquoises[edit | edit source]

The turquoise gemstone is the namesake for the color. Credit: .

Turquoise at right is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula CuAl6(PO4)4(OH)8·4H2O.

Umbozerites[edit | edit source]

Umbozerite is from Karnasurt Mt., Lovozero Massif, Kola, Russia, size 4.2 cm. Credit: Weirdmeister.{{free media}}

The IMA-CNMNC approved mineral symbol is Ubz.[6]

Umbozerites have the chemical formula Na
3
Sr
4
Th[Si(O,OH
(3-4)
]
8
, IMA formula Na
3
Sr
4
ThSi
8
(O,OH)
24
, common impurities: Ti,Ce,Fe,U,Mn,Ca,Ba,K, and Crystal System: Amorphous.[143]

Environment: In ussingite veinlets cutting alkalic rocks, type locality: Umbozero (Lake Umba), Kola Peninsula, Russia, dark brown prismatic umbozerite masses in pegmatite rock, Metamict - Mineral originally crystalline, now amorphous due to radiation damage, Pseudo Tetragonal - Crystals show a tetragonal shape, Umbozerite is Radioactive as defined in 49 CFR 173.403, greater than 70 Bq / gram.[144]

Occurrence: In pneumatolytic-hydrothermal veins cutting alkalic rocks in the upper part of a differentiated alkalic massif, Crystal Data: Metamict; tetragonal after recrystallization[145]

Association: Ussingite, sphalerite, belovite, manganoan pectolite, lorenzenite, niobium-bearing minerals of the lomonosovite group.[145]

Distribution: Found on Mts. Karnasurt and Punkaruaiv, near Lake Umba, Lovozero massif, Kola Peninsula, Russia.[145]

Uranophanes[edit | edit source]

Uranophane is a calcium uranium silicate hydrate mineral. Credit: United States Geological Survey.

Uranophane Ca(UO
2
)
2
(SiO
3
OH)
2
·5H
2
O
is a rare calcium uranium [nesosilicate] hydrate mineral that forms from the oxidation of uranium bearing minerals. Uranophane is also known as uranotile. It has a yellow color and is radioactive.

Vauxites[edit | edit source]

Widgiemoolthalites[edit | edit source]

Widgiemoolthalite (bright green) is intermingled with gaspéite (yellow-green). Field of view is three millimeters (0.12 in). Credit: Leon Hupperichs.{{free media}}

"Widgiemoolthalite is a rare hydrated nickel(II) carbonate mineral with the chemical formula (Ni,Mg)5(CO3)4(OH)2·5H2O. Usually bluish-green in color, it is a brittle mineral formed during the weathering of nickel sulfide. Present on gaspéite surfaces".[146]

Willemseites[edit | edit source]

Falcondoite and willemseite are rare nickel, magnesium silicates found in a serpentinized harzbergite massif or an obducted ophiolite at a plate collision of oceanic crust with continental crust. Credit: Robert M. Lavinsky.{{free media}}

Falcondoite and willemseite in the image on the right are rare nickel, magnesium silicates found in a serpentinized harzbergite massif or an obducted ophiolite at a plate collision of oceanic crust with continental crust. The locality is in the Dominican Republic, which is the Type Locality for falcondoite. This very showy, bright green thin crust is mostly green falcondoite, with just a bit of lighter, olive willemseite.

Wllemseite has the chemical formula Ni
3
Si
4
O
10
(OH)
2
.

Zoisites[edit | edit source]

In 1967, a purple-blue variety of zoisite, named tanzanite after its country of discovery, was found near the slopes of Mount Kilimanjaro on the border of Tanzania and Kenya. Credit: The University of Arizona Mineral Museum.
The tanzanite shown is a rough stone and a cut stone. Credit: Didier Descouens.
A rough sample of tanzanite is pictured. Credit: Wela49.

Tanzanite, a variety of zoisite that is purple-blue member of the epidote group.[15]

On the right is both a rough stone and a cut stone of tanzanite. Tanzanite is the blue/purple variety of the mineral zoisite (a calcium aluminium hydroxy silicate) with the formula (Ca2Al3(SiO4)(Si2O7)O(OH))]. Tanzanite is noted for its remarkably strong trichroism, appearing alternately sapphire blue, violet and burgundy depending on crystal orientation.[147] Tanzanite can also appear differently when viewed under alternate lighting conditions. The blues appear more evident when subjected to fluorescent light and the violet hues can be seen readily when viewed under incandescent illumination. A rough violet sample of tanzanite is third down at left.

Tanzanite in its rough state is usually a reddish brown color. It requires artificial heat treatment to 600 °C in a gemological oven to bring out the blue violet of the stone.[148]

Tanzanite is found only in the foothills of Mount Kilimanjaro.

Tanzanite is universally heat treated in a furnace, with a temperature between 550 and 700 degrees Celsius, to produce a range of hues between bluish-violet to violetish-blue. Some stones found close to the surface in the early days of the discovery were gem-quality blue without the need for heat treatment.

Zoisite has the chemical formula Ca2Al3Si3O12OH.[15]

Hypotheses[edit | edit source]

  1. Variations in rocks from one mineral composition into another can occur with each rock type.
  2. Oxidanes that are various ices may be produced by orbital cycling.

See also[edit | edit source]

References[edit | edit source]

  1. Geissler, P. L.; Dellago, C.; Chandler, D.; Hutter, J.; Parrinello, M. (2001). "Autoionization in liquid water". Science 291 (5511): 2121–2124. doi:10.1126/science.1056991. PMID 11251111. https://web.archive.org/web/20070625233942/http://gold.cchem.berkeley.edu:8080/Pubs/DC174.pdf. Retrieved 2017-10-25. 
  2. Marx, D.; Chandra, A; Tuckerman, M.E. (2010). "Aqueous Basic Solutions: Hydroxide Solvation, Structural Diffusion, and Comparison to the Hydrated Proton". Chem. Rev. 110 (4): 2174–2216. doi:10.1021/cr900233f. PMID 20170203. 
  3. Kamal Abu-Dari; Kenneth N. Raymond; Derek P. Freyberg (1979). "The bihydroxide (H
    3
    O
    2
    ) anion. A very short, symmetric hydrogen bond". J. Am. Chem. Soc. 101 (13): 3688–3689. doi:10.1021/ja00507a059.
     
  4. Greenwood, p. 1168
  5. IUPAC SC-Database A comprehensive database of published data on equilibrium constants of metal complexes and ligands
  6. 6.00 6.01 6.02 6.03 6.04 6.05 6.06 6.07 6.08 6.09 6.10 6.11 6.12 6.13 6.14 6.15 6.16 Warr, L.N. (2021). "IMA-CNMNC approved mineral symbols". Mineralogical Magazine 85: 291-320. https://www.cambridge.org/core/journals/mineralogical-magazine/article/imacnmnc-approved-mineral-symbols/62311F45ED37831D78603C6E6B25EE0A. 
  7. Handbook of Mineralogy - Abhurite
  8. 8.0 8.1 Mindat.org - Abhurite
  9. Richard V. Gaines, H. Catherine W. Skinner, Eugene E. Foord, Brian Mason, and Abraham Rosenzweig: "James Dwight Dana's new mineralogy", p. 401. John Wiley & Sons, 1997
  10. Memet, J. B. (2007). "The corrosion of metallic artefacts in seawater: descriptive analysis". In Dillmann, P.. Corrosion of Metallic Heritage Artefacts: Investigation, Conservation and Prediction of Long Term Behaviour. Elsevier. pp. 152–169. doi:10.1533/9781845693015.152. ISBN 9781845693015. 
  11. Vandiver, Pamela B.; Goodway, Martha; Mass, Jennifer L. (2002-01-01). Materials Issues in Art and Archaeology VI: Symposium Held November 26-30, 2001, Boston, Massachusetts, U.S.A.. Materials Research Society. ISBN 9781558996489. https://books.google.com/books?id=7YM-AQAAIAAJ&hl=en&sa=X&ved=0ahUKEwiv2dL5se_YAhUU7GMKHYrgBfQQ6AEISzAG. 
  12. ActinoliteWebmineral.org
  13. Handbook of Mineralogy
  14. http://rruff.geo.arizona.edu/doclib/hom/adamite.pdf Handbook of Mineralogy
  15. 15.0 15.1 15.2 15.3 15.4 15.5 Willard Lincoln Roberts; George Robert Rapp Jr.; Julius Weber (1974). Encyclopedia of Minerals. New York, New York, USA: Van Nostrand Reinhold Company. pp. 693. ISBN 0-442-26820-3. 
  16. Handbook of Mineralogy
  17. 17.0 17.1 Handbook of Mineralogy
  18. Webmineral data
  19. Hudson Institute of Mineralogy (31 October 2015). "Afwillite". Hudson Institute of Mineralogy. Retrieved 2015-11-05.
  20. 20.0 20.1 Kusachi, I, Henmi, C. And Henmi K. (1989) Afwillite and jennite from Fuka, Okayama Prefecture. Japan. Miner J. 14, 279-292.
  21. Barthemy, D. (2000) Afwillite Mineral Data, (http://webmineral.com/data/Afwillite.shtml)
  22. 22.0 22.1 Klein, C. and Dutrow, K. (2007) Manual of Mineral Science. 23rd Edition, 63, 596
  23. 23.0 23.1 23.2 23.3 Malik, K. M. A & Jeffery J. W. (1976) A re-investigation of the structure of afwillite. Acta Crystallographica, B32, 475.
  24. Megaw H. D. (1952). The structure of afwillite. Acta Crystallographica, 5, 477.
  25. 25.0 25.1 Dietrich J. E., Orliac M., Permingeat F. (1969) L’agardite, une nouvelle espèce minérale, et le problème du chlorotile, Bulletin de la Société Française de Minéralogie et de Cristallographie 92, 420–434.
  26. 26.0 26.1 Nickel E. H., Mandarino J. A. (1987) Procedures involving the IMA Commission on New Minerals and Mineral Names and guidelines on mineral nomenclature, American Mineralogist 72, 1031–1042.
  27. Walenta K., Theye T. (2004) Agardite-(Ce) of the Clara mine in the central Black Forest, Aufschluss 55, 17–23.
  28. Pekov I. V., Chukanov N. V., Zadov A. E., Voudouris P., Magganas A., Katerinopoulos A. (2011) Agardite-(Nd), NdCu
    6
    (AsO
    4
    )
    3
    (OH)
    6
    ·3H
    2
    O
    , from the Hilarion Mine, Lavrion, Greece: mineral description and chemical relations with other members of the agardite-zálesíite solid-solution system, Journal of Geosciences 57, 249–255.
  29. Fehr T., Hochleitner R. (1984) Agardite-La. Ein neues mineral von Lavrion, Griechenland, Lapis 9, 22–37.
  30. Sejkora J., Novotný P., Novák M., Šrein V., Berlepsch P. (2005) Calciopetersite from Domašov nad Bystricí, Northern Moravia, Czech Republic, a new mineral species of the mixite group, The Canadian Mineralogist 43, 1393–1400.
  31. Wise W. S. (1978) Parnauite and goudeyite, two new copper arsenate minerals from the Majuba Hill Mine, Pershing County, Nevada, American Mineralogist 63, 704–708.
  32. Schrauf A. (1880) Ueber Arsenate von Joachimsthal. 1. Mixit, ein neues Kupferwismuthhydroarsenat, Zeitschrift für Krystallographie und Mineralogie (in German) 4, 277–285.
  33. Williams P. A., Hatert F., Pasero M., Mills S. J. (2014) IMA Commission on new minerals, nomenclature and classification (CNMNC) Newsletter 20. New minerals and nomenclature modifications approved in 2014. Mineralogical Magazine 78, 549–558.
  34. Peacor D. R., Dunn P. J. (1982) Petersite, a REE and phosphate analog of mixite, American Mineralogist 67, 1039–1042.
  35. Walenta K., Theye T. (2005) Plumboagardite, a new mineral of the mixite group from an occurrence in the Southern Black Forest, Neues Jahrbuch für Mineralogie, Abhandlungen 181, 219–224.
  36. Sejkora J., Rídkošil T., Šrein V. (1999) Zálesíite, a new mineral of the mixite group, from Zálesí, Rychlebské hory Mts., Czech Republic, Neues Jahrbuch für Mineralogie, Abhandlungen 175, 105–124.
  37. Anthony J. W., Bideaux R. A., Bladh K. W., and Nichols M. C. (1990) Handbook of Mineralogy, Mineral Data Publishing, Tucson Arizona, USA, by permission of the Mineralogical Society of America.
  38. K. Walenta: "Die Mineralien des Schwarzwaldes", Weise (Munich), 1992.
  39. Sejkora J., Pauliš P., Kopista J.: Agardit-(Y) z ložiska Sn-W Cínovec v Krušných horách (Česká republika). Bulletin mineralogicko-petrografického oddělení Národního muzea v Praze, 2011, 19, 1, 64–68.
  40. LAPIS 24 (7/8) 1999; Wendel, W. and Markl, G. (1999) Lavrion: Mineralogische Klassiker und Raritäten für Sammler. LAPIS 24 (7/8): 34–52.
  41. Palenzona, A., Armellino, G., Bulgarelli, G. (1994): Le agarditi della Liguria. Rivista Mineralogica Italiana, 4/1994, 354–356.
  42. 42.0 42.1 Anthony, Bideaux, Bladh, Nichols: "Handbook of Mineralogy", Vol. 4, 2000.
  43. Gebhard, G. (1999): Tsumeb II. A Unique Mineral Locality. GG Publishing, Grossenseifen, Germany.
  44. Siuda R., K. Gal-Solymos, Kruszewski L., 2006: Agardite-(La)-duftite and scorodite-köttigite-like mineral paragenesis from supergenic zone of the Miedzianka deposit (Rudawy Janowickie Mts., Poland) – preliminary report. Mineralogia Polonica Special Papers, 29, 192–195.
  45. Stalder, H. A., Wagner, A., Graeser, S. and Stuker, P. (1998): "Mineralienlexikon der Schweiz", Verlag Wepf & Co. (Basel), p. 24.
  46. Goley, P. and Williams R. (1995) Cornish Mineral Reference Manual. Endsleigh Publications.
  47. Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 323.
  48. Ixfd64 (4 November 2006). "Agrinierite". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 16 November 2021.
  49. "Agrinierite Mineral Data (Webmineral)". Retrieved 16 November 2021.
  50. "Agrinierite (Handbook)" (PDF). Retrieved 16 November 2021.
  51. "Agrinierite (Mindat)". Retrieved 16 November 2021.
  52. 52.0 52.1 52.2 Aheylite. Handbook of Mineralogy
  53. 53.0 53.1 53.2 Eugene E. Foord and Joseph E. Taggart, Jr., A reexamination of the turquoise group: the mineral aheylite, plane rite (redefined), turquoise and coeruleolactite, Mineralogical Magazine, February 1998, Vol. 62(1), pp. 93-111
  54. 54.0 54.1 Aheylite. Mindat.org
  55. Aheylite. Webmineral
  56. 56.0 56.1 Ajoite. Handbook of Mineralogy. Retrieved on 2011-10-09.
  57. 57.0 57.1 Gaines, et al (1997) Dana's New Mineralogy, Eighth Edition. Wiley
  58. Ajoite. Mindat.org (2011-08-16). Retrieved on 2011-10-09.
  59. Bruce Cairncross (2004). Field guide to rocks & minerals of Southern Africa. Struik. p. 172. ISBN 978-1-86872-985-2. https://books.google.com/books?id=7yJkQkWROvoC. Retrieved 9 October 2011. 
  60. Ernst A.J. Burke (2008): "Tidying up Mineral Names: an IMA-CNMNC Scheme for Suffixes, Hyphens and Diacritical marks". Mineralogical Record, volume 39, issue 2.
  61. Jongsik Kim and Clare P. Grey (2010), "Li Solid-State MAS NMR Study of Local Environments and Lithium Adsorption on the Iron(III) Oxyhydroxide, Akaganeite (β-FeOOH)". Chemistry of Materials, volume 22, pages 5453–5462. doi:10.1021/cm100816h
  62. 62.0 62.1 C. Rémazeilles and Ph. Refait (2007): "On the formation of β-FeOOH (akaganéite) in chloride-containing environments". Corrosion Science, volume 49, issue 2, pages 844-857. doi:10.1016/j.corsci.2006.06.003
  63. "Mineral 314-687: Akaganeite". Mindat.org database, accessed on 2019-02-12.
  64. Matsuo Nambu (1968): "岩手県赤金鉱山産新鉱物赤金鉱 (β-FeOOH) について (New mineral Akaganeite, β-FeOOH, from Akagane Mine, Iwate Prefecture, Japan)", Journal of the Japanese Association of Mineralogists, Petrologists and Economic Geologists, volume 59, issue 4, pages 143-151,doi:10.2465/ganko1941.59.143
  65. Alan Lindsay Mackay (1962): "β-ferric oxyhydroxide - akaganéite", in Mineralogical Magazine and Journal of the Mineralogical Society, volume 33, issue 259, pages 270-280. doi:10.1180/minmag.1962.033.259.02 Cites a private communication by Matsuo Nambu (1961). Note: the diacritic in the title is incorrect, see Burke (2008). Reviewed by Mandarino (1963) in American Minralogist
  66. J. A. Mandarino (1963): "New Mineral Names: Akaganéite". American Mineralogist, volume 48, issues 5-6, page 711. Short review of Mackay's communication (1962) in Mineralogical Magazine. Note: the diacritic in the title is incorrect.
  67. Carter, John; Viviano-Beck, Christina; Loizeau, Damien; Bishop, Janice; Le Deit, Laetitia (1 June 2015). "Orbital detection and implications of akaganéite on Mars". Icarus 253: 296–310. doi:10.1016/j.icarus.2015.01.020. ISSN 0019-1035. 
  68. 69.0 69.1 P B Moore, P K Sen Gupta and E O Schlemper (1989). "Akrochordit (Akrochordite)". American Mineralogist Crystal Structure DB. Retrieved 26 November 2021.
  69. Dana (1959). "Akrochordite". Retrieved 26 November 2021.
  70. 71.0 71.1 Dana (1922). "Akrochordite Mineral Data". WebMineral. Retrieved 26 November 2021.
  71. Mindat Akrochordite
  72. Handbook of Mineralogy
  73. Aksaite
  74. 75.0 75.1 Dal Negro A, Ungaretti L, Sabelli C (1971) The crystal structure of aksaite American Mineralogist 56 1553-1566, https://rruff.info/doclib/am/vol56/AM56_1553.pdf
  75. Clark, A. M.; Fejer, E. F.; Creesy, G; Tandy, P. C. (1988). "Ashoverite, a new mineral, and other polymorphs of Zn(OH)
    2
    from Milltown, Ashover, Derbyshire"
    . Mineralogical Magazine 52 (368): 699–702. doi:10.1180/minmag.1988.052.368.14. http://rruff.geo.arizona.edu/doclib/mm/vol52/MM52_699.pdf.
     
  76. https://rruff.info/doclib/hom/ashoverite.pdf
  77. http://webmineral.com/data/Ashoverite.shtml#.YYSqdC1h0RY
  78. Handbook of Mineralogy: Magnesioaxinite
  79. Mindat.org
  80. "The Ancient Library: Smith, Dictionary of Greek and Roman Antiquities". December 20, 2005. pp. 321, right col., under BLUE.
  81. 82.0 82.1 V. Montoro (1942). "Crystal Structure of Bayerite". Ricerca Sciencia 13: 565. https://www.jstage.jst.go.jp/article/bcsj1926/31/1/31_1_140/_article. Retrieved 2015-10-28. 
  82. W. O. Milligan (1951). "Recent X-Ray Diffraction Studies on the Hydrous Oxides and Hydroxides". The Journal of Physical Chemistry 55 (4): 497-507. doi:10.1021/j150487a003. http://pubs.acs.org/doi/abs/10.1021/j150487a003. Retrieved 2015-10-28. 
  83. Goro Yamaguchi; Kenichi Sakamoto (1958). "Crystal Structure of Bayerite". Bulletin of the Chemical Society of Japan 31 (1): 140-1. doi:10.1246/bcsj.31.140. https://www.jstage.jst.go.jp/article/bcsj1926/31/1/31_1_140/_article. Retrieved 2015-10-28. 
  84. 85.0 85.1 85.2 George Y. Chao; Judith Baker; Ann P. Sabina; Andrew C. Roberts (1985). "Doyleite, A New Polymorph of Al(OH)3, and its Relationship to Bayerite, Gibbsite and Nordstrandite". Canadian Mineralogist 23: 21-8. http://rruff.info/doclib/cm/vol23/CM23_21.pdf. Retrieved 2015-10-28. 
  85. Raffaella Demichelis; Michele Catti; Roberto Dovesi (2009). "Structure and stability of the Al (OH) 3 polymorphs doyleite and nordstrandite: a quantum mechanical ab initio study with the crystal06 code". The Journal of Physical Chemistry C 113 (16): 6785-91. doi:10.1021/jp810084c. http://pubs.acs.org/doi/abs/10.1021/jp810084c. Retrieved 2015-10-28. 
  86. G.S.E. Antipas; N. Papassiopi; A. Xenidis (2014). "On the elusive anti-bayerite structure". Solid State Ionics 255: 65-73. doi:10.1016/j.ssi.2013.11.052. http://www.sciencedirect.com/science/article/pii/S0167273813006486. Retrieved 2015-10-28. 
  87. Mineral Data Pub. Handbook of Mineralogy
  88. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
  89. 90.0 90.1 90.2 Carrboydite Mindat
  90. 91.0 91.1 Carrboydite Mineral Data
  91. 92.0 92.1 Wefers, Karl; Misra, Chanakya (1987). Oxides and hydroxides of aluminum. Alcoa Research Laboratories. OCLC 894928306. http://worldcat.org/oclc/894928306. 
  92. N.N. Greenwood and A. Earnshaw, "Chemistry of Elements", 2nd edition, Butterworth and Heinemann, 1997
  93. Saalfeld, H.; Wedde, M. (1974). "Refinement of the crystal structure of gibbsite, Al(OH)3". Zeitschrift für Kristallographie 139: 129–135. https://rruff.info/doclib/zk/vol139/ZK139_129.pdf. 
  94. Gibbsite on Galleries.com
  95. "Gillardite". Retrieved 6 November 2021.
  96. http://rruff.geo.arizona.edu/doclib/hom/glaucophane.pdf Handbook of Mineralogy
  97. IMA/CNMNC List of Mineral Names; November 2018
  98. Hugo Strunz, Ernest H. Nickel: Strunz Mineralogical Tables. Chemical-structural Mineral Classification System. Volume 9, E. Schweizerbart’sche Verlagsbuchhandlung (Nägele u. Obermiller), Stuttgart, 2001, ISBN 3-510-65188-X, page 294
  99. 100.0 100.1 100.2 Glaukosphaerite
  100. 101.0 101.1 101.2 101.3 Hydrohonessite
  101. Nickel, Ernest H.; Wildman, John E. (September 1981). "Hydrohonessite-a new hydrated Ni-Fe hydroxysulphate mineral; its relationship to honessite, carrboydite, and minerals of the pyroaurite group". Mineralogical Magazine 44: 333-7. 
  102. Deer WA, Howie RA, Zussman J (1992). An Introduction to the Rock-forming Minerals (2nd ed.). Harlow: Longman. ISBN 9780470218099. 
  103. Pohl, Walter L. (2011). Economic geology: principles and practice: metals, minerals, coal and hydrocarbons – introduction to formation and sustainable exploitation of mineral deposits. Chichester, West Sussex: Wiley-Blackwell. pp. 331. ISBN 9781444336627. https://books.google.com/books?id=Jq2rpN-6AccC. 
  104. Anthony JW, Bideaux RA, Bladh KW, Nichols MC, ed (1995). Kaolinite, In: Handbook of Mineralogy: Silica, silicates. Tucson, Arizona, USA: Mineral Data Publishing. ISBN 9780962209734. OCLC 928816381. http://www.handbookofmineralogy.org/pdfs/kaolinite.pdf. 
  105. Perry DL (2011). Handbook of Inorganic Compounds (2nd ed.). Boca Raton: Taylor & Francis. ISBN 9781439814611. OCLC 587104373. 
  106. 107.0 107.1 107.2 Kambaldaite
  107. 108.0 108.1 Ernest H. Nickel and Bruce W. Robinson (1985). "Kambaldaite--a new hydrated Ni-Na carbonate mineral from Kambalda, Western Australia". American Mineralogist 70: 419-422. https://rruff.info/rruff_1.0/uploads/AM70_419.pdf. Retrieved 2 December 2021. 
  108. Hurlbut, Cornelius S.; Klein, Cornelis (1985). Manual of Mineralogy, Wiley, (20th edition ed.). ISBN 0-471-80580-7
  109. Lepidolite on Mindat.org
  110. H. Nechamkin, The Chemistry of the Elements, McGraw-Hill, New York, 1968.
  111. 112.0 112.1 http://webmineral.com/data/Libethenite.shtml Webmineral
  112. 113.0 113.1 113.2 113.3 113.4 113.5 http://www.mindat.org/min-2394.html Mindat
  113. "Malachite". WebExhibits. 2001. Retrieved 2007-12-08.
  114. Malachite. Mindat
  115. http://www.mindat.org/min-8771.html
  116. American Mineralogist (1975): 60: 863-871
  117. 118.0 118.1 Ray L. Frost, Marilla J. Dickfos, and B. Jagannadha Reddy (2008). "Raman spectroscopy of hydroxy nickel carbonate minerals nullaginite and zaratite". Journal of Raman Spectroscopy 39 (9): 1250-6. https://eprints.qut.edu.au/14554/2/14554.pdf. Retrieved 19 February 2020. 
  118. Handbook of Mineralogy
  119. 120.0 120.1 120.2 https://www.mindat.org/min-3044.html Otwayite
  120. Nickel, E.H., Robinson, B.W., Davis, C.E.S. and MacDonald, R.D. (1977) Otwayite, a new nickel mineral from Western Australia. American Mineralogist: 62: 999-1002. http://rruff.info/rruff_1.0/uploads/AM62_999.pdf
  121. Handbook of Mineralogy
  122. "Paratacamite". Retrieved 6 November 2021.
  123. 124.0 124.1 124.2 "Paravauxite". Retrieved 2021-10-11.
  124. 125.0 125.1 "Paravauxite Mineral Data". Retrieved 2021-10-11.
  125. Gordon, Samuel G. (1923). "Vauxite and Paravauxite, Two New Minerals from Llallagua, Bolivia". Proceedings of the Academy of Natural Sciences of Philadelphia 75: 261–270. ISSN 0097-3157. https://www.jstor.org/stable/4063881. 
  126. "Paravauxite, In: Dakota Matrix Minerals". Retrieved 2021-10-11.
  127. Anthony. "Paravauxite, In: Dakota Matrix Minerals" (PDF). Retrieved 26 November 2021.
  128. 129.0 129.1 "Webmineral". Retrieved 2013-03-21.
  129. 130.0 130.1 130.2 130.3 130.4 "Mineralogy Database". Mindat. Retrieved 2013-03-21.
  130. Mindat w/ localities
  131. Webmineral
  132. Woodruff, Robert E.& Manuel Frisch, Blue pectolite in the Dominican Republic, Gems & Gemology, Winter 1989
  133. 134.0 134.1 Woodruff, Robert E. (January 1986). "Larimar -- Beautiful, blue and baffling". Article in Lapidary Journal. Retrieved 2009-09-24.
  134. 135.0 135.1 135.2 135.3 "Handbook of Mineralogy" (PDF).
  135. 136.0 136.1 "Portlandite: Mineral information, data and localities". www.mindat.org.
  136. Masterson, W. L., & Hurley, C. N. (2004). Chemistry: Principles and Reactions, 5th Ed. Thomson Learning, Inc. (p 331)"
  137. 138.0 138.1 Webmineral data
  138. 139.0 139.1 Ralph, Jolyon. "Sweetite" Mindat.org. 2010. 17 Sep 2010
  139. 140.0 140.1 Handbook of Mineralogy
  140. Clark, A.M., Fejer, E.E., Couper, A.G., and Jones G.C. (1984) Sweetite, a new mineral from Derbyshire. Mineralogical Magazine, 48, 267-269.
  141. "Sweetite" (http://webmineral.com/data/Sweetite.shtml). Mineral Data. http://webmineral.com/data/Sweetite.shtml. Retrieved 7 November 2010.
  142. "Umbozerite". Retrieved 19 November 2021.
  143. "Umbozerite Mineral Data". Retrieved 19 November 2021.
  144. 145.0 145.1 145.2 "Umbozerite" (PDF). Retrieved 19 November 2021.
  145. Collin Knopp-Schwyn, et al. (25 August 2019). "Widgiemoolthalite". WikiJournal of Science 2 (1): 7. doi:10.15347/wjs/2019.007. https://en.wikiversity.org/wiki/WikiJournal_of_Science/Widgiemoolthalite. Retrieved 9 February 2020. 
  146. E. Skalwold. Pleochroism: trichroism and dichroism in gems. Nordskip.com. http://www.nordskip.com/pleochroism.html. Retrieved 2011-08-29. 
  147. YourGemologist / International School of Gemology Study of Heat Treatment. Yourgemologist.com. http://www.yourgemologist.com/heattreatment.html. Retrieved 2011-08-29. 

External links[edit | edit source]