mineral

Tumbled labradorite

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

AI-generated identification · may be incorrect

Dark gray-green, rounded and polished, with blue-green iridescent flashes (labradorescence) and a vitreous to pearly luster. Mohs hardness 6–6.5; triclinic crystal structure; two cleavages near 90°; specific gravity about 2.68–2.72.

Identified September 2, 2026More mineral →

Explore Tumbled 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 slowly cooled mafic igneous rocks such as gabbro, anorthosite, and basaltic bodies through crystallization of feldspar-rich magma. Most gem-quality material is associated with Precambrian anorthosite complexes; the exact source cannot be determined from the image.

Uses & applications

Used as a lapidary stone for cabochons, beads, carvings, and tumbled stones, and occasionally as decorative architectural stone. It is popular in mineral collecting and jewelry.

Geological facts

Its color flashes result from light interference between microscopic exsolution layers within the feldspar, not from surface coating. The strongest flash appears when the stone is viewed at particular angles.

Field identification & locations

Identify it by gray body color, feldspar-like cleavage, moderate hardness, and blue or green angular flashes under moving light; it is commonly found in Canada, Madagascar, Finland, Norway, and Russia. The pictured specimen is likely a commercially tumbled piece.