Alexandrite

Alexandrite is a variety of the Chrysoberyl species. It's name is derived from the Russian Czar, Alexander the 2nd who was in power when it was discovered in the 1830s. It's color changing properties, dependant on the light source, are what makes this gemstone unique, and sought after. Larger specimens show their color changing properties best and can be very expensive. Sunlight changes it's hue to greens, blues or purples, while showing influences of light red under artificial incandescent light sources.

Although originally discovered in the Urals, that supply has been essentially depleted. Currently mined from Zimbabwe, Sri Lanka and most recently from Brazil. Smaller deposits have also been found in Tanzania, Burma and Madagascar.

Primarily fashioned into faceted gemstones, Alexandrite can be quite expensive. Chemically identical lab created gems are available, having the same color changing properties for considerably less cost. This should not be confused with an artificial gemstone called "Zandrite" which boasts complete color changing properties, but is essentially a specially treated glass.

STATS:
Color: Changes from green to light red
Mohs' Hardness Scale: 8 1/2
Density: 3.70 - 3.78
Transparency: Transparent to Opaque