Labradorite

Physical Properties

Hardness: 6.0–6.5 (Mohs scale); Color: Pale green, blue, colorless, grey-white; Luster: Vitreous to pearly; Crystal structure: Triclinic; Cleavage: Perfect; Specific gravity: 2.68 to 2.72; Phenomenon: Labradorescence (iridescence caused by internal light reflection).

Formation & Geological History

Primary formation occurs in mafic igneous rocks such as basalt and gabbro. It is an intermediate to calcic member of the plagioclase series. Geological age varies by deposit, ranging from Proterozoic to more recent formations.

Uses & Applications

Predominantly used as a gemstone in jewelry, for decorative carvings, and as ornamental stone in architectural countertops or floor tiles.

Geological Facts

Labradorite's characteristic schiller effect is caused by the interference of light within microscopic layers of exsolution lamellae. According to Inuit legend, the Northern Lights (Aurora Borealis) were once trapped within rocks on the coast of Labrador until an ancient warrior struck them with his spear, freeing most of the lights while some remained in the stone.

Field Identification & Locations

Identify in the field by rotating the specimen until a bright, metallic flash of blue, gold, or green color (the labradorescence) appears. It is commonly found in Canada (Labrador), Madagascar, Norway, and Finland.

Identified on: 4/20/2026

Mode: Standard