mineral

Tumbled labradorite

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

AI-generated identification · may be incorrect

Typically gray to blue-gray with iridescent blue flash (labradorescence), glassy to pearly luster, triclinic crystal structure, and two good cleavage directions; Mohs hardness 6–6.5, specific gravity about 2.68–2.72.

Identified August 26, 2026More mineral →

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Physical properties

Formation & geological history

Forms mainly in mafic igneous rocks such as basalt, gabbro, and anorthosite as magma cools; many gem-quality specimens formed during Precambrian geological events, though age varies by deposit.

Uses & applications

Used as a decorative stone, cabochon, tumbled stone, jewelry, carvings, and architectural facing; it is valued primarily for its optical flash.

Geological facts

The blue sheen is caused by light interference within microscopic lamellae produced during feldspar exsolution. The pictured rounded, polished form is consistent with a tumbled specimen.

Field identification & locations

Identify it by gray body color, curved blue flash that changes with viewing angle, feldspar cleavage, and hardness below quartz; common sources include Madagascar, Finland, Canada, Norway, and Russia.