Editing Internet Texts/Gemstones/Alexandrite

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Alexandrite[edit]

Alexandrite is one of the rarest and most valuable gemstones. It was discovered by chance during a search for emeralds near Yekaterinburg in 1833, on the day of Alexander the Second's birthday anniversary (hence the name).[1] It is a very valuable variety of chrysoberyl, which ranks as the third-hardest gemstone, right after diamond and corundum.

Alexandrite changes its color depending upon the nature of ambient lighting. It is emerald-colored or grass-green in daylight and purple-reddish in artifical light. Its color varies also from red to orange-yellowish depending on the angle from which it is looked at.

Alexandrite

Basic properties[edit]

Composition Al2BeO4
Class Oxydes and hydroxydes
Crystal system Rhombic
Mohs' hardness 8,5
Fracture Conchoidal
Cleavage Imperfect
Lustre Glassy
Streak White
Localities Tanzania, Brazil, Sri Lanka, Republic of South Africa, India, Zimbabwe, Tasmania

References[edit]

  1. Minerały i kamienie szlachetne by RBA Collecionables, S.A., ISBN 978-83-7813-150-2, 2012.