Labradorite
Plagioclase Feldspar var. Labradorite · Semi-Precious Gemstone and Decorative Stone
Crystal System
Triclinic, commonly found as massive, granular, or tabular crystals with polysynthetic twinning.
Mineral Group
Silicates (Tectosilicate subgroup, Feldspar group)
Chemical Formula
(Na,Ca)(Al,Si)4O8
Formation Process
Igneous, particularly in mafic igneous rocks such as gabbro, basalt, and anorthosites, as well as in pegmatites through slow cooling of magma.
About This Crystal
A polished, tumbled stone displaying a dark, greyish-green body color with a characteristic iridescent flash of blue light (labradorescence) on its surface. It has a vitreous to sub-vitreous luster and is opaque to translucent.
Physical Characteristics
Body color ranges from dark grey, brown, to greenish-grey with vibrant iridescent optical flashes; streak is white; perfect cleavage in two directions at approximately 87 degrees; fracture is uneven to conchoidal; specific gravity is around 2.71 to 2.74; tenacity is brittle.
Optical Properties
Biaxial positive with a refractive index ranging between 1.559 and 1.568; exhibits strong labradorescence (schiller effect) caused by light interference from microscopic lamellar intergrowths.
Hardness & Durability
Origin Region
Madagascar, Finland (Spectrolite), Canada (Labrador), Australia, Mexico, and the United States.
Hardness & Durability
Mohs hardness of 6 to 6.5; moderate to good durability, but susceptible to cleavage cracking if struck sharply; suitable for pendants, earrings, and rings with protective settings.
Care & Maintenance
Clean with warm soapy water and a soft cloth; avoid ultrasonic cleaners, steam cleaners, and harsh chemical acids; store separately from harder gems to prevent scratching.
Rarity & Value
Common to uncommon; high-grade material with full-spectrum labradorescence commands higher prices, though tumbled stones like this are generally affordable and widely accessible.
Special Characteristics
Labradorescence, a specialized form of adularescence producing vibrant spectral flashes of blue, green, gold, and copper light.
Lore & History
Discovered in Labrador, Canada in 1770; deeply connected in Inuit legend to the Northern Lights trapped in rocks; often used in metaphysical practices for transformation, protection, and enhancing intuition, primarily associated with the throat and third eye chakras.