mineral

Labradorite

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

Hardness: 6-6.5 on Mohs scale. Color: Gray-green, dark gray, brown, or colorless with iridescent flashes of blue, green, gold, or copper (labradorescence). Luster: Vitreous to pearly. Crystal structure: Triclinic. Specific gravity: 2.68-2.72.

Hardness: 6-6
Luster: Vitreous to pearly

Identified August 7, 2026More mineral →

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Physical properties

Formation & geological history

Forms in mafic igneous rocks such as basalt, gabbro, and anorthosite, as well as in metamorphic and pegmatitic rocks. It cools slowly from a melt deep within the Earth's crust, allowing the microscopic lamellar intergrowths that cause labradorescence to develop.

Uses & applications

Widely used as a semi-precious gemstone in jewelry (cabochons, pendants, rings), decorative ornaments, and architectural countertops.

Geological facts

Labradorite is famous for its optical phenomenon called 'labradorescence,' which is caused by light diffraction interference from microscopic lamellar intergrowths of plagioclase feldspar.

Field identification & locations

Easily identified by its dark, unassuming exterior that flashes brilliant iridescent colors of blue and green when rotated in the light. Major deposits are found in Labrador (Canada), Madagascar, Finland, Australia, and Russia.