Labradorite
Plagioclase Feldspar var. Labradorite · Semi-Precious Gemstone and Decorative Stone
Crystal System
Triclinic; typically forms as massive, granular, or tabular crystals, rarely as distinct crystals
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
(Na,Ca)(Al,Si)4O8
Formation Process
Igneous and metamorphic processes, primarily crystallizing slowly from cooling magma in intrusive rocks like anorthosite, gabbro, and basalt
About This Crystal
A polished, tumbled stone showing a dark gray-green body color with subtle chatoyant flashes typical of labradorescence, possessing a vitreous to greasy luster and opaque to translucent transparency
Physical Characteristics
Dark gray to greenish-blue body color, white streak, good cleavage in two directions at approximately 87 degrees, uneven to conchoidal fracture, specific gravity of 2.68-2.72, brittle tenacity
Optical Properties
Biaxial positive with refractive indices between 1.559 and 1.568, displaying strong labradorescence (schiller effect) due to lamellar intergrowths
Hardness & Durability
Origin Region
Madagascar, Finland, Canada, Australia, Mexico, and the United States; forms in mafic igneous rocks
Hardness & Durability
Mohs hardness of 6 to 6.5, fair to good toughness, sensitive to thermal shock and strong acids, moderate wearability for jewelry
Care & Maintenance
Clean with warm soapy water and a soft cloth, avoid ultrasonic cleaners, harsh chemicals, and sudden temperature changes; store separately to prevent scratching
Rarity & Value
Common to uncommon; high-grade gem-quality material with vibrant multi-colored labradorescence is more valuable, typically very affordable for tumbled stones
Special Characteristics
Labradorescence, an optical phenomenon caused by light diffraction through microscopic lamellae of albite and anorthite
Lore & History
Associated with transformation, mysticism, and strengthening intuition in modern crystal healing; traditionally linked to the wind elements and the third eye chakra