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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.
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.
Alexandrite in sizes over three carats are very rare. Today, several labs can produce synthetic lab-grown stones with the same chemical and physical properties as natural alexandrite. Several methods can produce flux-grown alexandrite, Czochralski (or pulled) alexandrite, and hydrothermally-produced alexandrite.
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
In the past, goshenite was used for manufacturing eyeglasses and lenses owing to its transparency. Nowadays, it is most commonly used for gemstone purposes. [45] [46] The gem value of goshenite is relatively low. However, goshenite can be colored yellow, green, pink, blue and in intermediate colors by irradiating it with high-energy particles.
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
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Menshikov Ruby, the world's second largest spinel set on top of the Great Imperial Crown of Russia Timur Ruby , believed to be a ruby until 1851, hence its name Black Prince's Ruby , the famous spinel mounted on the Imperial State Crown of the United Kingdom