mineral

Likely raw labradorite-bearing feldspar

Labradorite, plagioclase feldspar (approximately NaAlSi₃O₈–CaAl₂Si₂O₈)

AI-generated identification · may be incorrect

Gray-green to blue-gray, translucent patches, vitreous to pearly luster, and blocky feldspar cleavage; Mohs hardness 6–6.5, specific gravity about 2.68–2.72. The blue flash (labradorescence) is characteristic, though the photograph is not definitive.

Identified August 11, 2026More mineral →

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Physical properties

Formation & geological history

Forms as an igneous feldspar in gabbroic, anorthositic, and basaltic rocks when magma cools; exsolution structures develop during cooling over geological time, commonly Precambrian to younger. Major localities include Labrador, Canada; Madagascar; Finland; Norway; and Russia.

Uses & applications

Used as decorative stone, countertops, facing stone, and cabochon jewelry; attractive rough is collected for its iridescent flashes.

Geological facts

Labradorescence comes from light interference in microscopic lamellae within the feldspar, not surface coating. The specimen may also be a related gray plagioclase or weathered mafic rock if no strong color flash appears.

Field identification & locations

Rotate it under a point light to look for blue, green, or gold flashes; test hardness against glass and inspect for two cleavage directions. Confirmatory identification requires microscopy or chemical testing.