mineral

Labradorite

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

Hardness: 6-6.5 on Mohs scale; Color: Gray to black with blue, green, or gold iridescence; Luster: Vitreous to pearly; Crystal structure: Triclinic; Cleavage: Perfect in two directions; Specific Gravity: 2.68-2.72

Hardness: 6-6
Color: Gray to black with blue, green, or gold iridescence
Luster: Vitreous to pearly

Identified July 1, 2026More mineral →

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Physical properties

Formation & geological history

Formed in igneous environments, typically in mafic rocks like basalt or gabbro, as well as in anorthosite. Its characteristic 'labradorescence' is caused by internal lamellar structures that diffract light as the mineral cools over geological time.

Uses & applications

Primarily used in jewelry as gemstones (cabochons), interior decoration (countertops), and as a popular specimen for crystal collectors and metaphysical practices.

Geological facts

First discovered in Labrador, Canada, in 1770. The striking flashes of light are known as the Schiller effect or labradorescence, caused by light hitting microscopic layers of differing composition within the stone.

Field identification & locations

Identify in the field by rotating the specimen under a bright light source to check for sudden flashes of blue or green color (labradorescence) against a dark gray background. Found extensively in Canada, Madagascar, and Norway.