Labradorite
Feldspar var. Labradorite (Plagioclase Series) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Triclinic; typically occurs in massive or granular habits in igneous rocks.
Mineral Group
Silicates (Subgroup: Tectosilicates; Plagioclase Feldspar Group)
Chemical Formula
(Ca,Na)(Al,Si)4O8
Formation Process
Igneous formation; crystallizes from mafic igneous rocks like basalt, gabbro, and norite, as well as in anorthosites.
About This Crystal
A dark grayish-green to black stone with a vitreous to pearly luster. This specimen is a tumbled/polished pebble showing characteristic labradorescence (schiller effect) and internal twinning planes.
Physical Characteristics
Color: Dark gray/green; Streak: White; Cleavage: Two directions at nearly 90 degrees; Fracture: Conchoidal to uneven; Specific Gravity: 2.68–2.72; Fluorescence: Generally inert.
Optical Properties
Biaxial (+/-) with refractive index 1.560–1.572. Displays 'Labradorescence', an optical phenomenon caused by light diffraction in lamellar twinning layers.
Hardness & Durability
Origin Region
Notably Labrador (Canada), Madagascar, Finland (Spectrolite), and Russia.
Hardness & Durability
Mohs Hardness: 6.0–6.5. Brittle tenacity with perfect cleavage, making it susceptible to cracking if struck hard.
Care & Maintenance
Clean with warm soapy water and a soft cloth; avoid ultrasonic cleaners, steam, and harsh chemicals. Store separately to prevent scratches.
Rarity & Value
Common; Value is driven by the intensity, variety, and coverage of the 'flash' color (blue, gold, green, or full spectrum).
Special Characteristics
Labradorescence (schiller effect), which creates shifting metallic colors when viewed from different angles due to internal structures.
Lore & History
Discovered in 1770 on Paul's Island, Labrador. Inuit lore suggests the Northern Lights were trapped inside the rocks. Traditionally associated with the Third Eye chakra and transformation.