History
Alexandrite was discovered in 1834 on Czar Alexander's birthday at an emerald mine near the Tokovaya River in Russia's Ural Mountains. This original deposit is now exhausted.
Physical Properties
Alexandrite is one of the world's hardest minerals; only diamonds and corundum are harder. It also absorbs certain colors, which, in turn, makes it change colors. The stone appears green or bluish-green in natural light and turns red or purple-red in incandescent light. Traditionally, the truer the minerals colors are to red and green the more valuable the mineral.
The Largest Score
In 1987 Brazil's Lavra de Hematita mine in Minas Gerias produced the world's largest find of gem-quality alexandrite. Gems weighing in at nearly 30 carats were produced at the mine in under three months.
Mining Alexandrite Today
Gravel deposits in Sri Lanka still produce a fair quantity of alexandrite. However, the country's last major find was in 1993, and production has since declined. India is the world's latest producer of clean alexandrite stones.
Fun Fact
Because red and green are the colors of the Russian Imperial Guard, alexandrite was named the official gemstone of Tsarist Imperial Russia.