mineral

Labradorite

Labradorite (Ca,Na)(Al,Si)4O8

Hardness: 6-6.5 Mohs. Color: Gray-green to dark gray with labradorescence (iridescent play of colors). Luster: Vitreous to pearly. Crystal structure: Triclinic. Cleavage: Perfect in two directions. Specific gravity: 2.68-2.72.

Hardness: 6-6
Luster: Vitreous to pearly

Identified May 18, 2026More mineral →

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Physical properties

Formation & geological history

Formed in mafic igneous rocks such as basalt and gabbro, as well as in some metamorphic rocks. It crystallizes from cooling magma in deep crustal environments. Notable deposits range from Proterozoic to more recent geological ages.

Uses & applications

Primarily used in jewelry for its optical effects, as well as in small carvings, ornaments, and as a popular specimen for mineral collectors. Some high-quality slabs are used in architectural cladding.

Geological facts

The iridescent effect is known as labradorescence, caused by internal lamellar twinning which diffracts light. It was first discovered on Paul's Island near the town of Nain in Labrador, Canada, in 1770.

Field identification & locations

Identify by the characteristic 'schiller' or flash of blue, gold, or green colors when rotated under light. Common in Labrador (Canada), Madagascar, Norway, and Russia. Look for gray stones that suddenly display metallic colors.