mineral

Tumbled labradorite

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

AI-generated identification · may be incorrect

Gray-brown body with strong blue iridescent flash (labradorescence), vitreous luster, and generally granular crystal structure; Mohs hardness 6–6.5, specific gravity about 2.68–2.72, with two cleavages near 90°. The rounded shape indicates polishing or tumbling.

Identified August 26, 2026More mineral →

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Physical properties

Formation & geological history

Forms in mafic igneous rocks such as basalt, gabbro, and anorthosite as magma cools; notable deposits are Precambrian, especially in Labrador, Canada, with major commercial material also from Madagascar and Finland.

Uses & applications

Used as a decorative stone, cabochons, beads, carvings, countertops, and collectible mineral specimens; vivid blue or multicolor flash commands the highest prices.

Geological facts

Its colors result from light interference within microscopic exsolution lamellae in the feldspar, not from surface coating. Spectral colors vary strongly with viewing angle and polished orientation.

Field identification & locations

Identify it by gray base color, plagioclase-like cleavage, moderate hardness, and shifting blue, green, or gold flash under directional light; common sources include Labrador, Madagascar, Finland, and Norway.