mineral

Alexandrite

Chrysoberyl (BeAl2O4)

Hardness: 8.5 Mohs scale; Color: Green/Blue-green in daylight, Red/Purplish-red in incandescent light (pleochroism); Luster: Vitreous; Crystal Structure: Orthorhombic; Cleavage: Distinct in one direction.

Hardness: 8
Luster: Vitreous

Identified April 6, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed in granitic pegmatites and mica schists where beryllium is present and silica is deficient, allowing chromium to substitute for aluminum. Most specimens are from the Phanerozoic eon.

Uses & applications

Primarily used as a rare and precious gemstone in high-end jewelry and as a prized specimen for mineral collectors.

Geological facts

First discovered in the Ural Mountains of Russia in 1830 and named after Tsar Alexander II. It is often described as 'emerald by day, ruby by night.'

Field identification & locations

Identified by its extreme hardness and dramatic color-change effect (Alexandrite effect). Found in Russia, Brazil, Sri Lanka, and East Africa. Use a penlight and daylight to check for color shifts.