mineral

Labradorite

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

Hardness: 6-6.5 on Mohs scale; Color: Gray to smoky black with iridescent play of colors (labradorescence); Luster: Vitreous to pearly; Crystal structure: Triclinic; Cleavage: Perfect in two directions.

Hardness: 6-6
Luster: Vitreous to pearly

Identified April 29, 2026More mineral →

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Physical properties

Formation & geological history

Formed in mafic igneous rocks, especially anorthosite, through the crystallization of magma. It is an intermediate member of the plagioclase feldspar series.

Uses & applications

Primarily used as a gemstone in jewelry, decorative carvings (like the skull shown), and as a luxury building material for countertops and wall cladding.

Geological facts

The iridescent effect, known as labradorescence, is caused by internal light reflections from lamellar intergrowths formed during the cooling of the mineral. In Finland, high-quality specimens are known as Spectrolite.

Field identification & locations

Identify in the field by looking for the blue, green, or gold 'flash' when tilted in the light. It is commonly found in Canada (Labrador), Madagascar, Russia, and Finland. Collectors look for high 'flash' coverage and vivid colors.