mineral

Polished labradorite slab

Labradorite, a calcium-rich plagioclase feldspar (approximately (Ca,Na)(Al,Si)₄O₈)

AI-generated identification · may be incorrect

Hardness 6–6.5 Mohs; typically gray, green, or blue with vivid iridescent flashes (labradorescence), vitreous luster, triclinic crystals, and two good cleavage directions. The pictured material appears polished and possibly resin-backed or mounted.

Identified September 13, 2026More mineral →

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Physical properties

Formation & geological history

Forms as an igneous feldspar in mafic intrusive rocks such as anorthosite, gabbro, and basaltic complexes, commonly during Precambrian to younger geological events. Optical color results from light interference in microscopic lamellae within the feldspar.

Uses & applications

Used for cabochons, carvings, decorative slabs, jewelry, and architectural facing stone; strongly iridescent pieces are most desirable.

Geological facts

Its blue-green flash changes with viewing angle and is not surface glitter. Labradorite belongs to the plagioclase feldspar solid-solution series.

Field identification & locations

Identify it by gray-green body color, angular feldspar cleavage, hardness, and angle-dependent blue-green flash; major sources include Madagascar, Canada, Finland, Norway, and Mexico. Avoid confusing it with treated glass or dyed stone.