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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.
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.
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
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 ...
However, new sources produced much larger faceted stones, the biggest faceted gem weighing 254 carats. This gem was found in Sri Lanka in 1990. Even though jeremejevite is a relatively durable stone, it should not be cleaned using ultrasound cleaning or steaming; the stone usually contains liquid inclusions, which could shatter the stone if ...
Demantoid is the green gemstone variety of the mineral andradite, a member of the garnet group of minerals.Andradite is a calcium- and iron-rich garnet.The chemical formula is Ca 3 Fe 2 (SiO 4) 3 with chromium substitution as the cause of the demantoid green color.
Certain synthetic color-change sapphires have a similar color change to the natural gemstone alexandrite and they are sometimes marketed as "alexandrium" or "synthetic alexandrite". However, the latter term is a misnomer: synthetic color-change sapphires are, technically, not synthetic alexandrites but rather alexandrite simulants .