Labradorite (Feldspar)

Physical Properties

Hardness: 6-6.5 on Mohs scale; Color: typically dark gray to gray-green with labradorescence; Luster: vitreous to pearly; Crystal structure: Triclinic; Cleavage: Perfect in two directions; Specific gravity: 2.68-2.72

Formation & Geological History

Formed in mafic igneous rocks such as basalt, gabbro, and norite. It crystallizes from cooling magma in intrusive environments. Notable deposits occur in Precambrian rock formations.

Uses & Applications

Primarily used as a gemstone in jewelry, decorative carvings, and as a high-end architectural stone for countertops or tiles.

Geological Facts

It is famous for the optical phenomenon known as labradorescence, which is caused by internal light reflections from submicroscopic layers of exsolution lamellae within the crystal structure.

Field Identification & Locations

Identify in the field by its dark base color and metallic iridescent flashes (blue, green, gold) when rotated under light. Major locations include Labrador (Canada), Madagascar, Russia, and Finland (Spectrolite).

Identified on: 4/22/2026

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