Blue Kyanite
Kyanite · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Triclinic; typically found in long, bladed, or tabular crystals, often radiating or in parallel aggregates.
Mineral Group
Silicates; Nesosilicate (Aluminosilicate)
Chemical Formula
Al2SiO5 (Aluminum Silicate)
Formation Process
Metamorphic; forms under high-pressure regional metamorphism of clay-rich sedimentary rocks (pelites). It is an indicator mineral of high-pressure environments.
About This Crystal
Elongated bladed crystal exhibiting a distinct denim-blue to sky-blue color. Features a splintery, fibrous texture with a vitreous to pearly luster. Transition from transparent to translucent with some opaque white streaks.
Physical Characteristics
Color: Blue with white or grey streaks; Streak: White; Cleavage: Perfect in one direction, good in another; Fracture: Splintery; Specific Gravity: 3.53–3.67; Fluorescence: Weak red under UV.
Optical Properties
Refractive Index: 1.712–1.734; Biaxial negative; Strong pleochroism (colorless to violet-blue to cobalt blue); Double refraction is present.
Hardness & Durability
Origin Region
Brazil, Nepal, India, Kenya, Switzerland, and USA (North Carolina/Connecticut); typically found in metamorphic schists and gneisses.
Hardness & Durability
Anisotropic hardness: 4.5 to 5 along the length of the crystal and 6.5 to 7 across the width. Brittle toughness; poor wearability for rings due to easy cleavage.
Care & Maintenance
Avoid ultrasonic cleaners and steam cleaning due to splintery nature. Clean with lukewarm soapy water and soft brush. Store separately to prevent scratching other stones or being crushed.
Rarity & Value
Relatively common; value is determined by transparency and color saturation. Deep cornflower blue 'gem-quality' crystals from Nepal command the highest prices. Treatments are rare.
Special Characteristics
Notable for its extreme anisotropy (directional hardness). Also shows 'chatoyancy' occasionally in high-quality fibrous specimens. Some crystals may contain 'ink-spot' color zoning.
Lore & History
Named from the Greek word 'kyanos' (blue). Historically used as a compass by travelers who believed it could use Earth's magnetic force. In metaphysical lore, it is believed to align all chakras instantly and is one of the few stones said to never accumulate negative energy.