mineral

Polished labradorite

Labradorite, plagioclase feldspar; approximately (Ca,Na)(Al,Si)₄O₈

AI-generated identification · may be incorrect

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

Identified August 9, 2026More mineral →

Explore Polished labradorite in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Forms in mafic igneous rocks such as basalt, gabbro, and anorthosite as calcium-rich plagioclase crystallizes from cooling magma. Not assignable to a precise age from the photograph; notable deposits include Precambrian rocks of Labrador, Canada, Madagascar, Finland, and Norway.

Uses & applications

Used as a decorative stone, cabochon, carving material, countertops, and collectible mineral specimens; strong iridescence increases jewelry value.

Geological facts

Its color flash results from light interference along microscopic exsolution lamellae within the feldspar. The specimen appears tumbled or polished, which can obscure cleavage and crystal form.

Field identification & locations

Confirm with a strong directional light for blue, green, or gold flash, glassy cleavage surfaces, and hardness near 6; visually similar gray feldspars and larvikite may lack the same flash.