Labradorite

Labradorite (Ca, Na)(Al, Si)4O8

Rock Type: mineral

Labradorite

Physical Properties

Hardness: 6–6.5 Mohs. Color: Typically dark gray to green; displays Labradorescence (iridescent play of blue, gold, and green). Luster: Vitreous to pearly. Crystal structure: Triclinic. Cleavage: Perfect in two directions.

Formation & Geological History

Formed in mafic igneous rocks such as basalt or gabbro through the crystallization of magma. It is an intermediate to calcic member of the plagioclase feldspar series.

Uses & Applications

Commonly used in jewelry (cabochons), interior design (countertops, tiles), and as a popular specimen for mineral collectors and practitioners of metaphysics.

Geological Facts

First discovered in 1770 on Paul\'s Island, near Labrador, Canada. The striking iridescent effect is caused by internal lamellar twinning which diffracts light, a phenomenon named labradorescence.

Field Identification & Locations

Identify in the field by rotating the rock under light to search for hidden flashes of blue or green. Found heavily in Canada, Madagascar, Finland, and Russia.

Identified on: 4/15/2026

Mode: Standard