mineral

Labradorite

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

AI-generated identification · may be incorrect

Hardness: 6-6.5 Mohs; Color: Gray to black with blue/green/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/gold iridescence
Luster: Vitreous to pearly

Identified June 29, 2026More mineral →

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Physical properties

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

Formation & geological history

Forms in mafic igneous rocks like basalt, gabbro, and norite through the crystallization of cooling magma. Common in Precambrian rocks over 1 billion years old.

Uses & applications

Primarily used as a gemstone in jewelry, for decorative carvings, and as a countertop material (Labrador Antique granite).

Geological facts

Exhibits a unique optical effect known as labradorescence, caused by light diffracting from submicroscopic layers within the mineral. It is often called the 'Aurora Borealis' of stones.

Field identification & locations

Identify in the field by rotating the specimen to catch the metallic blue or green flashes (schiller effect) against a dark gray background. Found extensively in Labrador, Canada, and Madagascar.