Alexandrite is one of the most precious gemstones and is the rarest variety of chrysoberyl mineral, Russia's national gem. It was discovered relatively late, on April 17, 1834 by the Finnish mineralogist N. Nordenskjöld in the Emerald Mines of the Urals.

Identification:
Color: yellow to emerald green, blue-green, gray-brown
System: rhombic
Hardness: 8.5
Glossy: glassy
Cleavage: distinct according to {110}
White scratch
Density: 3,75 g⋅cm − 3
Other: strong pleochroism