Labradorite

Physical Properties

Hardness: 6.0-6.5; Color: Dark grey to grey-black with labradorescence; Luster: Vitreous to pearly; Crystal structure: Triclinic; Cleavage: Good in two directions; Specific Gravity: 2.68-2.72.

Formation & Geological History

Formed in mafic igneous rocks like basalt and gabbro through the slow cooling of silica-poor magma. Most significant deposits range from the Mesoproterozoic era.

Uses & Applications

Primarily used as a semi-precious gemstone in jewelry, decorative ornaments, and used in building facades or countertops (granite-alternative).

Geological Facts

It is famous for 'labradorescence', an optical effect created by internal light reflections from submicroscopic layers of exsolution lamellae within the feldspar crystal.

Field Identification & Locations

Identify by rotating it under light to look for flashes of blue, green, or gold. Located commonly in Canada (Labrador), Madagascar, Norway, and Finland.

Identified on: 5/2/2026

Mode: Standard