Labradorite
Plagioclase Feldspar var. Labradorite · Semi-Precious Gemstone and Decorative Stone
Crystal System
Triclinic, typically found in massive, granular, or tabular crystal habits.
Mineral Group
Silicates (Tectosilicate, Feldspar group)
Chemical Formula
(Ca,Na)(Al,Si)4O8
Formation Process
Igneous formation through the slow cooling of molten magma deep within the Earth's crust, particularly in mafic intrusive and extrusive rocks.
About This Crystal
A polished, tumbled smooth stone displaying a dark greenish-gray to brownish body color with characteristic internal fracture lines and a flash of iridescent color play known as labradorescence.
Physical Characteristics
Dark gray to brownish body color, white streak, good cleavage in two directions at nearly right angles, uneven to conchoidal fracture, specific gravity around 2.71, brittle tenacity, and typically non-fluorescent.
Optical Properties
Biaxial with a refractive index between 1.560 and 1.572, displaying notable labradorescence (schiller effect) caused by microscopic lamellar intergrowths scattering light.
Hardness & Durability
Origin Region
Madagascar, Finland, Canada (Labrador), Russia, and Australia; typically forms in mafic igneous rocks like gabbro, basalt, and anorthosite.
Hardness & Durability
Mohs hardness of 6 to 6.5, fair to good toughness, sensitive to thermal shock and harsh acids, moderate wearability for jewelry with protective settings.
Care & Maintenance
Clean with warm soapy water and a soft cloth; avoid ultrasonic cleaners, harsh chemical detergents, and prolonged exposure to direct sunlight.
Rarity & Value
Common to uncommon, with higher value assigned to specimens exhibiting full-spectrum labradorescence, transparency, and lack of deep surface fractures.
Special Characteristics
Displays pronounced labradorescence, an optical phenomenon showing vibrant flashes of peacock blue, green, gold, and copper colors when viewed at specific angles.
Lore & History
Associated in modern metaphysical lore with transformation, protection, and enhancing intuition. Historically discovered in Labrador, Canada, and featured in Inuit legends relating the stone to the frozen fire of the Aurora Borealis.