Labradorite

Physical Properties

Hardness: 6-6.5; Color: Dark grey to grey-black with iridescent flashes (labradorescence); Luster: Vitreous to pearly; Crystal Structure: Triclinic; Cleavage: Perfect in two directions.

Formation & Geological History

An intermediate member of the plagioclase series, typically forming in mafic igneous rocks such as basalt, gabbro, and norite through slow cooling of magma.

Uses & Applications

Primarily used as a gemstone for jewelry, in lapidary work for ornamental carvings, and occasionally as decorative architectural stone (countertops or tiles).

Geological Facts

The unique internal reflections are known as 'labradorescence,' caused by light diffracting off microscopic layers of exsolution lamellae within the crystal.

Field Identification & Locations

Commonly found in Labrador (Canada), Finland, Madagascar, and Russia. Identified in the field by its dark body color contrasted against vivid flashes of electric blue, green, or gold when tilted.

Identified on: 5/17/2026

Mode: Standard