Labradorite
Feldspar group, Plagioclase series (Anorthite-Albite solid solution), var. Labradorite · Semi-Precious Gemstone and Decorative Stone
Crystal System
Triclinic, typically forming massive, granular, or tabular crystals with polysynthetic twinning
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
(Na,Ca)(Al,Si)4O8
Formation Process
Igneous and metamorphic, crystallizing slowly from cooling magmas, commonly found in mafic igneous rocks like anorthosite, gabbro, and basalt
About This Crystal
Polished into a puffy heart shape, this specimen displays a dark grey to smoky body color with characteristic internal lamellar structures. It exhibits a vitreous to pearly luster and showcases distinct iridescent optical phenomena across its smooth surface.
Physical Characteristics
Body color ranges from dark grey, brown, to near black with iridescent flashes; white streak; perfect cleavage in two directions meeting at oblique angles; uneven to conchoidal fracture; specific gravity of approximately 2.68 to 2.72; brittle tenacity; usually inert to weak fluorescence under UV light
Optical Properties
Biaxial positive with a refractive index between 1.559 and 1.570; exhibits strong birefringence and a distinctive optical phenomenon known as labradorescence, producing flashes of peacock blue, green, gold, and copper
Hardness & Durability
Origin Region
Madagascar, Finland, Canada (Labrador), Australia, Mexico, and Russia
Hardness & Durability
Mohs hardness of 6 to 6.5; fair to good toughness; sensitive to thermal shock and harsh acids; moderate wearability for jewelry, requiring protective settings particularly for rings
Care & Maintenance
Clean gently using warm soapy water and a soft cloth; avoid ultrasonic cleaners, steam cleaners, and harsh chemical solvents; store separately from harder gemstones to prevent scratching
Rarity & Value
Common to uncommon depending on the intensity and coverage of labradorescence; high-quality specimens with full spectrum flashes command higher prices; typically untreated
Special Characteristics
Labradorescence, caused by the interference of light within microscopic lamellar intergrowths (exsolution lamellae) of albite and anorthosite
Lore & History
Discovered in Labrador, Canada, in 1770, labradorite is rich in Inuit lore, where it was believed to have fallen from the frozen fires of the Aurora Borealis. In modern metaphysical practices, it is considered a stone of transformation, enhancing intuition, shielding the aura, and balancing the third eye and throat chakras.