Astrominerals

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Kamacite, Nantan (Nandan) iron meteorites, Nandan County, Guangxi Zhuang Autonomous Region, China. Size: 4.8×3.0×2.8 cm. The Nantan irons, a witnessed fall in 1516, have a composition of 92.35% iron and 6.96% nickel. Credit: Robert M. Lavinsky.{{free media}}

Minerals found within asteroids or asteroidal meteorites, including meteorites not yet assigned to an astronomical object of likely origin other than Earth are listed and classified here.

The minerals are classified by their geominerals or general minerals classifications.

The kamacite in the image on the right is believed to be from an asteroid that produced the Nantan meteorite.

Minerals occurring on Mars or in meteorites likely originating from Mars can be called Areiominerals, where Areios is the Greek adjective of Ares, the Greek version of Mars (Roman).

Minerals occurring on the Moon or in meteorites likely originating from the Moon can be called Selenominerals.

Minerals occurring on Venus or in meteorites likely originating from Venus can be called Aphroditominerals, although so far there are no known meteorites from Venus found on Earth.

Minerals occurring on Mercury or in meteorites likely originating from Mercury can be called Hermiominerals.

Allendeites[edit | edit source]

Allendeites have the formula Sc
4
Zr
3
O
12
.

Allendeite is an oxide mineral.[1] Its International Mineralogical Association (IMA) symbol is Aed.[2] Allendeite was discovered in a small ultrarefractory inclusion within the Allende meteorite.[1] This inclusion has been named ACM-1.[1] It is one of several scandium rich minerals that have been found in meteorites.[1] Allendeite is trigonal, with a calculated density of 4.84 g/cm3.[1] The new mineral was found along with hexamolybdenum.[1] These minerals, are believed to demonstrate conditions during the early stages of the Solar System, as is the case with many CV3 carbonaceous chondrites such as the Allende meteorite.[1] It is named after the Allende meteorite that fell in 1969 near Pueblito de Allende, Chihuahua, Mexico.[1]

Allendeite was found as nano-crystals in an ultrarefractory inclusion in the Allende meteorite.[1] The Allende meteorite has shown to be full of new minerals, after nearly forty years it has produced one in ten of the now known minerals in meteorites.[1] This CV3 carbonaceous chondrite was the largest ever recovered on earth and is referred to as the best-studied meteorite in history.[1] The inclusion has only been viewed via electron microscopy.[1] The sample is one centimeter in diameter and has been entrusted to the Smithsonian Institution's National Museum of Natural History with the catalog number USNM7554.[1] One crystal studied is a single 15 x 25 micron size with included perovskite, various osmium-iridium-molybdenum-tungsten alloys, and scandium-stabilized tazheranite.[1] In fact, all allendeite was in contact with perovskite.[1] The grains are [anhedral, with no observable crystal forms or twinning.[1]

Various scandium rich minerals have been found in meteorites, including; davisite, panguite, kangite, tazheranite, thortveitite, and eringaite.[1] Of these, allendeite is the most Sc rich, with only pretulite containing substantially more scandium.[1]

Color, streak, luster, Mohs hardness, tenacity, cleavage, fracture, density, and refractive index could not be observed because the grain size was too small and the section bearing the mineral was optically thick.[1]

Antitaenites[edit | edit source]

"Antitaenite is a meteoritic metal alloy mineral composed of iron and nickel, 20-40% Ni (and traces of other elements) that has a face centered cubic crystal structure."[3]

It exists as a new mineral species occurring in both iron meteorites and in chondrites[4]

The pair of minerals antitaenite and taenite constitute the first example in nature of two minerals that have the same crystal structure (face centered cubic) and can have the same chemical composition (same proportions of Fe and Ni) - but differ in their electronic structures: taenite has a high magnetic moment whereas antitaenite has a low magnetic moment.[5]

This difference arises from a high-magnetic-moment to low-magnetic-moment transition occurring in the Fe-Ni bi-metallic alloy series.[6]

Kamacites[edit | edit source]

This image is a cross-section of the Laguna Manantiales meteorite showing Widmanstätten patterns. Credit: Aram Dulyan.{{free media}}

"Kamacite is an alloy of iron and nickel, which is only found on earth in meteorites. The proportion iron:nickel is between 90:10 to 95:5; small quantities of other elements, such as cobalt or carbon may also be present. The mineral has a metallic luster, is gray and has no clear cleavage although the structure is isometric-hexoctahedral. Its density is around 8 g/cm³ and its hardness is 4 on the Mohs scale. It is also sometimes called balkeneisen."[7]

The Nantan irons, a piece is on the right, a witnessed fall in 1516, have a composition of 92.35% iron and 6.96% nickel.

The Nantan meteorite is an iron meteorite that belongs to the IAB meteorite (IAB) group and the MG (main group) subgroup.[8]

The fall of the meteorite might have been observed in 1516, but it is difficult to assess if this event is connected with the pieces that were retrieved in 1958.[9]

The meteorite burst during passage through the atmosphere and the pieces were scattered in a strewn field 28 kilometres (17 mi) long and 8 kilometres (5.0 mi) wide near the city of Nantan, Nandan County, Guangxi (China).[9]

The fragments were not retrieved until the 1950s when they were gathered for smelting to make metal for the growing industrialization of China, but it was found that the meteoric iron contained too much nickel for smelting.[9]

The Nantan meteorite was classified as an IIICD in 2000, but was reclassified as an IAB-MG in 2006. 9,500 kilograms (20,900 lb) have been retrieved, the largest fragment having a mass of 2,000 kilograms (4,400 lb). Most fragments show strong signs of weathering, due to the long time it took to retrieve them. The meteoric iron has a Nickel concentration of 6.96%.[10]

Orthopyroxenes[edit | edit source]

Bunburra Rockhole is an anomalous basaltic achondritic meteorite.[11][12][13] Originally classified as a eucrite,[13] it was thought to belong to a group of meteorites that originated from the asteroid 4 Vesta,[14][15][12] but has since been reclassified based on oxygen and chromium isotopic compositions. It was observed to fall on July 21, 2007, 04:43:56 local time, by the Desert Fireball Network (DFN).[13][15] Two fragments weighing 150g and 174g were recovered by the DFN at 31°21.0′S, 129°11.4′E in the [Nullarbor Desert region, South Australia in November of the same year.[13][15] This is the first meteorite to be recovered using the Desert Fireball Network observatory.[13][15]

Bunburra rockhole is described as a basaltic monomict breccia, which is composed of three different lithologies that can be distinguished by their grain sizes. There is no evidence of weathering, and very few shock features are present. The majority of the meteorite is subophitic in texture.

Primary mineralogy:

  • Orthopyroxene, Ferrosilite Fs
    62.5
    Wo
    3.6
    , ~ 1 mm in size.
  • Plagioclase, Anorthite An
    84.1
    to An
    88.2
    ~ 1 mm in size.
  • Augite, Ferrosilite Fs
    27.7
    Wo
    43.0
    as lamella within pyroxene.

Oxygen Isotope analyses have contributed to the classification of meteorites and identification of potential origins. Typically, meteorites of a particular classification will exhibit similar oxygen isotope signatures that are often distinct from meteorites that have originated from other planetary bodies. Equilibrated asteroids, planets and moons are predicted to produce meteorites with distinctive oxygen isotope signatures based on the composition and environment of the planetary body. Bunburra Rockhole exhibits a range of oxygen isotope signatures that vary as a function of the three different lithological subtypes present.[15] This indicates that the parent body of the sample may not have been fully equilibrated at the time of crystallization of the meteorite components in this sample.[15]

The oxygen and chromium isotope results from Bunburra Rockhole are quite different to the bulk of the HED meteorite clan.[16][17] Recently published Cr and O isotope data[17] suggest that Bunburra Rockhole is isotopically similar to Asuka 881394;[18] another outlier of the HED group. Such outliers also exhibit differences in minor element ratios to the HED clan.[17] However, the mineralogy and composition of the Bunburra Rockhole imply it did originate from a differentiated, V-type asteroid,[15][17] but not from 4-Vesta.

This type of brecciated achondrite is similar to terrestrial igneous rocks and has undergone igneous processing on a differentiated parent body.[19] Bunburra Rockhole likely came from a differentiated body smaller than 4-Vesta, as this would have resulted in faster cooling and perhaps incomplete differentiation. The differences in oxygen and chromium isotopes and variable trace element compositions relative to the bulk HED measurements are consistent and supportive of this hypothesis. This rock, along with other meteorites close in chemical composition and texture to HED meteorite (HEDs), are evidence that there may have been a large number of differentiated bodies once present in our Solar System, and that the igneous processing and activity on those bodies was rather complex.[17]

Bunburra Rockhole was observed to fall using the Desert Fireball Network observatory in Australia. It was found to have an Aten-type orbit. Upon examination of the rock's recent orbital history, it was found to have been ~ 0.04 AU from Venus in September 2001. Modelling to understand the evolution of the object's orbit revealed a 98% probability that the object came from the inner region of the main asteroid belt.

Panguites[edit | edit source]

Panguites have the formula (Ti4+
,Sc,Al,Mg,Zr,Ca)
1.8
O
3

Panguite is a type of titanium oxide mineral first discovered as an inclusion within the Allende meteorite, and first described in 2012.[20][21]

The hitherto unknown meteorite mineral was named for the ancient Chinese god Pan Gu, the creator of the world through the separation of yin (earth) from yang (sky).[20]

The mineral's chemical formula is (Ti4+
,Sc,Al,Mg,Zr,Ca)
1.8
O
3
. The elements found in it are titanium, scandium, aluminium, magnesium, zirconium, calcium, and oxygen. Samples from the meteorite include some which are zirconium rich. The mineral was found in conjunction with the already identified mineral davisite, within an olivine aggregate.[22]

Panguite is in a class of refractory minerals that formed under the high temperatures and extremely varied pressures present in the early Solar System, up to 4.5 billion years ago. This makes panguite one of the oldest minerals in the Solar System. Zirconium is a key element in determining conditions prior to and during the Solar System's formation.

Chi Ma, director of the Geological and Planetary Sciences division's Analytical Facility at the California Institute of Technology was the lead author of its first peer-reviewed article, published in American Mineralogist.[23] Ma has been leading a nano mineralogy investigation, since 2007, of primitive meteorites, including the well studied Allende meteorite. The mineral was first described in a paper submitted to the 42nd annual Lunar and Planetary Science Conference in 2011.[24]

Tetrataenites[edit | edit source]

"Tetrataenite is a native metal found in meteorites with the composition FeNi."[25]

It is one of the mineral phases found in meteoric iron.[26][27][28]

See also[edit | edit source]

References[edit | edit source]

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 Beckett, John R. and Rossman, George R. = Allendeite (Sc
    4
    Zr
    3
    O
    12
    and hexamolybdenum (Mo, Ru, Fe), two new minerals from an ultrarefractory inclusion from the Allende meteorite
    . American Mineralogist, Volume 99, pages 654-666, 2014. doi:10.2138/am.2014.4667
  2. 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. 
  3. "Antitaenite". San Francisco, California: Wikimedia Foundation, Inc. May 7, 2013. Retrieved 2013-09-01.
  4. D.G. Rancourt and R.B. Scorzelli. Low Spin γ-Fe-Ni (γLS) Proposed as a New Mineral in Fe-Ni-Bearing Meteorites: Epitaxial Intergrowth of γLS and Tetrataenite as Possible Equilibrium State at ~20-40 at % Ni. Journal of Magnetism and Magnetic Materials 150 (1995) 30-36
  5. D.G. Rancourt, K. Lagarec, A. Densmore, R.A. Dunlap, J.I. Goldstein, R.J. Reisener, and R.B. Scorzelli. Experimental Proof of the Distinct Electronic Structure of a New Meteoritic Fe-Ni Alloy Phase. Journal of Magnetism and Magnetic Materials 191 (1999) L255-L260
  6. K. Lagarec, D.G. Rancourt, S.K. Bose, B. Sanyal, and R.A. Dunlap. Observation of a composition-controlled high-moment/low-moment transition in the face centered cubic Fe-Ni system: Invar effect is an expansion, not a contraction. Journal of Magnetism and Magnetic Materials 236 (2001) 107-130.
  7. "Kamacite". San Francisco, California: Wikimedia Foundation, Inc. August 4, 2013. Retrieved 2013-09-01.
  8. "Nantan". Meteoritical Society.
  9. 9.0 9.1 9.2 "Nandan meteorite (Nantan meteorite)". mindat.org. Retrieved 24 December 2012.
  10. "Nantan Nickel-Iron Meteorites". Cutting Rocks. Retrieved 24 December 2012.
  11. Mittlefehldt, David W.; McCoy, Timothy J.; Goodrich, Cyrena Anne; Kracher, Alfred (1998). "Non-chondritic Meteorites from Asteroidal Bodies". Reviews in Mineralogy and Geochemistry. 36 (1): 4.1–4.195.
  12. 12.0 12.1 "Meteoritical Bulletin: Recommended classifications". www.lpi.usra.edu. Retrieved 2017-05-09.
  13. 13.0 13.1 13.2 13.3 13.4 "Meteoritical Bulletin: Entry for Bunburra Rockhole". www.lpi.usra.edu. Retrieved 2017-05-09.
  14. Takeda, Hiroshi (1997). "Mineralogical records of early planetary processes on the howardite, eucrite, diogenite parent body with reference to Vesta". Meteoritics & Planetary Science 32 (6): 841–853. doi:10.1111/j.1945-5100.1997.tb01574.x. 
  15. 15.0 15.1 15.2 15.3 15.4 15.5 15.6 Bland, Philip A.; Spurný, Pavel; Towner, Martin C.; Bevan, Alex W. R.; Singleton, Andrew T.; Bottke, William F.; Greenwood, Richard C.; Chesley, Steven R. et al. (2009-09-18). "An Anomalous Basaltic Meteorite from the Innermost Main Belt". Science 325 (5947): 1525–1527. doi:10.1126/science.1174787. ISSN 0036-8075. PMID 19762639. 
  16. Wiechert, U. H.; Halliday, A. N.; Palme, H.; Rumble, D. (2004-04-30). "Oxygen isotope evidence for rapid mixing of the HED meteorite parent body". Earth and Planetary Science Letters 221 (1–4): 373–382. doi:10.1016/S0012-821X(04)00090-1. 
  17. 17.0 17.1 17.2 17.3 17.4 Benedix, G. K.; Bland, P. A.; Friedrich, J. M.; Mittlefehldt, D. W.; Sanborn, M. E.; Yin, Q. -Z.; Greenwood, R. C.; Franchi, I. A. et al. (2017-07-01). "Bunburra Rockhole: Exploring the geology of a new differentiated asteroid". Geochimica et Cosmochimica Acta 208: 145–159. doi:10.1016/j.gca.2017.03.030. http://oro.open.ac.uk/53837/1/53837.pdf. 
  18. Sanborn, M. E.; Yin, Q.-Z. (2014-03-01). "Chromium Isotopic Composition of the Anomalous Eucrites: An Additional Geochemical Parameter for Evaluating Their Origin". Lunar and Planetary Science Conference 45 (1777): 2018. 
  19. Hutchison, Robert (2004-09-16). Meteorites: A Petrologic, Chemical and Isotopic Synthesis. Cambridge University Press. https://books.google.com/books?id=SKWTi7cwLIUC. 
  20. 20.0 20.1 "Caltech scientists find new primitive mineral in meteorite". Eurekalert. 26 June 2012. Retrieved 26 June 2012.
  21. Jeanna Bryner (26 June 2012). "1969 fireball meteorite reveals new ancient mineral". NBCNews.com.
  22. Wired
  23. Ma C. et al. 2012. "Panguite, (Ti4+,Sc,Al,Mg,Zr,Ca)1.8O3, a new ultra-refractory titania mineral from the Allende meteorite: Synchrotron micro-diffraction and EBSD", American Mineralogist, Volume 97, pages 1219–1225
  24. Ma, Chi; Oliver Tschauner; John R. Beckett; Boris Kiefer; George R. Rossman; Wenjun Liu. "Discovery of Panguite, a New Ultra-Refractory Titania Mineral in Allende". 42nd Lunar and Planetary Science Conference (2011). Retrieved 28 June 2012.
  25. "Tetrataenite". San Francisco, California: Wikimedia Foundation, Inc. July 24, 2013. Retrieved 2013-09-01.
  26. "Tetrataenite". webmineral.com.
  27. Mindat.org - Tetrataenite
  28. Handbook of Mineralogy - Tetrataenite

External links[edit | edit source]

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