mineral

Chrysoberyl (Cyclic Twin)

Beryllium Aluminum Oxide (BeAl2O4)

Hardness: 8.5 (Mohs scale); Color: Yellowish-green to brownish-green; Luster: Vitreous; Crystal Structure: Orthorhombic (often forming pseudo-hexagonal cyclic twins); Cleavage: Distinct {011}; Specific Gravity: 3.5–3.8

Hardness: 8
Color: Yellowish-green to brownish-green
Luster: Vitreous

Identified March 14, 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, often through metamorphic processes where beryllium is present. Commonly found in alluvial deposits due to its high hardness and resistance to weathering.

Uses & applications

Primarily used as a gemstone (including varieties like Alexandrite and Cat's Eye) and highly valued by mineral collectors for its unique twinning habits.

Geological facts

This specimen displays a famous 'V-twin' or 'heart-shaped' cyclic twin. Chrysoberyl is the third-hardest natural gemstone after diamond and sapphire. The variety 'Alexandrite' is famous for its color-change property under different lighting.

Field identification & locations

Identify in the field by its extreme hardness, vitreous luster, and characteristic trilling or V-shaped twinning. Major locations include Brazil, Sri Lanka, Madagascar, and Russia (Urals).

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral