Hobbies And Interests
History and Availablity
Alexandrite was discovered in pegmatite deposits being mined for emeralds in the Ural Mountains of Russia in 1834. The mineral was named for the Czar, Alexander II, on whose birthday it was discovered. Alexandrite deposits also occur in Brazil's famed Minas Gerais mining district and Sri Lanka, though some gemologists consider gems from Russia superior. More recent discoveries have occurred in India and Tanzania.
Appearance
Chrysoberyl is itself a semiprecious stone and the extremely rare Alexandrite variety is highly prized. While chrysoberyl is typically yellowish or brownish, Alexandrite is both red and green. The mineral's most striking property is that it changes colors: when viewed in daylight, Alexandrite is green; but when viewed in artificial light it is red.
The mineral's hardness is approximately 8 1/2, between rutile and corundum (ruby) on the Moh's hardness scale. Chrysoberyl is a durable mineral that facets well, though the cat's eye variety is typically cut into cabachons.
Similar Minerals
Topaz, heliodor, peridot and yellow sapphire are similar in appearance, though none displays Alexandrite's color-changing capability.
Price
Alexandrite is among the world's rarest minerals, so specimens command extremely high prices. Prices for top-quality stones approached $100,000 per carat in the period between 2007 and 2008.