Formula: BeAl₂O₄

Species: Oxides

Colour: Green shades, emerald-green, greenish white, yellowish green, greenish brown, yellow, blue

Lustre: Vitreous

Hardness: 8½

Specific Gravity: 3.75

Crystal System: Orthorhombic

Name: From the Greek χρυσός, golden, and βήρυλλος, beryl, in allusion to the colour.

Type Locality: Brazil

The green (chromium-bearing) gem variety that shows a colour change under different light sources is called alexandrite.