Labradorite
Plagioclase Feldspar (var. Labradorite) · Semi-Precious Gemstone / Collector Mineral
Crystal System
Triclinic; typically found in massive, granular, or blocky habits rather than distinct crystals.
Mineral Group
Silicates (Tectosilicates); Feldspar Group
Chemical Formula
(Ca,Na)(Al,Si)4O8 with traces of iron and manganese
Formation Process
Igneous formation; crystallizes from mafic igneous rocks like basalt and gabbro, or in metamorphic rocks.
About This Crystal
Generally dark grey to brownish-green base color with a dull to vitreous luster. Features a signature iridescent play of color called labradorescence.
Physical Characteristics
Grey to dark green body color; white streak; perfect cleavage in two directions; conchoidal to uneven fracture; specific gravity 2.68-2.72.
Optical Properties
Biaxial (+); Labradorescence (interference of light in microscopic leaf-like lamellae); RI 1.559-1.573; Weak birefringence.
Hardness & Durability
Origin Region
Labrador (Canada), Madagascar, Finland (Spectrolite), and Russia.
Hardness & Durability
6 to 6.5 on Mohs scale; brittle toughness; sensitive to pressure and high heat.
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid ultrasonic cleaners, steam, and harsh chemicals. Store separately to prevent scratching.
Rarity & Value
Common globally but high-quality specimens with intense 'flash' are uncommon. Value is based on the intensity and spectrum of the labradorescence.
Special Characteristics
Labradorescence (Schiller effect) appearing as flashes of blue, green, yellow, or orange when rotated under light.
Lore & History
Discovered in 1770 on Paul's Island, Labrador. Inuit lore suggests the Northern Lights were trapped within the rocks. Often associated with transformation and protection.