Labradorite
Plagioclase Feldspar var. Labradorite · Semi-Precious Gemstone and Decorative Stone
Crystal System
Triclinic, typically found in massive, tabular, or cleavable granular habits
Mineral Group
Silicates, specifically Tectosilicates (Feldspar group)
Chemical Formula
(Ca,Na)(Al,Si)4O8
Formation Process
Igneous, predominantly crystallizing from mafic and intermediate magmas such as gabbro, basalt, and anorthosite
About This Crystal
A tumbled, polished smooth specimen displaying a dark blue to grey body color with subtle areas of metallic iridescence known as labradorescence, opaque to translucent with a vitreous to pearly luster on cleavage surfaces
Physical Characteristics
Color ranges from dark grey, brown, or black with flashes of blue, green, and gold; white streak; good cleavage in two directions at nearly right angles; uneven to conchoidal fracture; specific gravity around 2.68-2.72; brittle tenacity
Optical Properties
Biaxial positive with a refractive index ranging from 1.559 to 1.568; exhibits strong labradorescence (a form of adularescence caused by lamellar intergrowths)
Hardness & Durability
Origin Region
Labrador (Canada), Madagascar, Finland, Australia, Russia, and Mexico
Hardness & Durability
Mohs hardness of 6 to 6.5; fair to good durability but vulnerable to cleavage planes and sudden impacts; suitable for most jewelry with protective settings
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid ultrasonic cleaners, harsh chemicals, and prolonged exposure to acids; store separately to prevent scratching by harder stones
Rarity & Value
Common to uncommon depending on the quality of the optical flash; value is determined by the vibrancy, coverage, and color spectrum of the labradorescence; generally affordable as tumbled stones and cabochons
Special Characteristics
Labradorescence, which produces striking flashes of peacock blue, green, and gold when viewed at specific angles due to light interference in microscopic lamellae
Lore & History
In Inuit legend, the Northern Lights were trapped in the rocks along the coast of Labrador until a warrior freed them with a spear; traditionally associated with transformation, strengthening intuition, and protecting the aura, linked to the throat and third eye chakras