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Tairus (Russian: Тайрус, a portmanteau of Тайско and Русский ()) is a synthetic gemstone manufacturer. It was formed in 1989 as part of Mikhail Gorbachev's perestroika initiative to establish a joint venture between the Russian Academy of Sciences and Tairus Created Gems Co Ltd. of Bangkok, Thailand.
Hydrothermal lab-grown alexandrite has identical physical and chemical properties to real alexandrite. [18] Some gemstones falsely described as lab-grown synthetic alexandrite are actually corundum laced with trace elements (e.g., vanadium) or color-change spinel and are not actually chrysoberyl.
Synthetic alexandrite is an artificially grown crystalline variety of chrysoberyl, composed of beryllium aluminum oxide (BeAl 2 O 4). The name is also often used erroneously to describe synthetically-grown corundum that simulates the appearance of alexandrite , but with a different mineral composition.
Alexandrite (variety of chrysoberyl): – Tsar Alexander II of Russia (1818–1881) Alforsite : Ba 5 Cl(PO 4 ) 3 – American geologist John T. Alfors (1930–2005) Allabogdanite : (Fe,Ni) 2 P – Alla Bogdanova , Geological Institute, Kola Science Centre of Russian Academy of Sciences
Gemstones of the World revised 5th edition, 2013 by Walter Schumann ISBN 978-1454909538 Smithsonian Handbook: Gemstones by Cally Hall, 2nd ed. 2002 ISBN 978-0789489852 hide
The Diamond Fund (Russian: Алмазный фонд) is a unique collection of gems, jewelry and natural nuggets, which are stored and exhibited in the Kremlin Armoury in Russia. The Fund was opened in 1967 and its collection dates back to the Russian Crown treasury instituted by Emperor Peter I of Russia in 1719.
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Alexandrite displays a colour change dependent upon light, along with strong pleochroism. The gem results from small-scale replacement of aluminium by chromium oxide, which is responsible for alexandrite's characteristic green to red colour change. Alexandrite from the Ural Mountains in Russia is green by daylight and red by incandescent light ...