Kyanite occurs in light to deep blue, white, gray, or green colors. Forming in pegmatite veins within metamorphic rock as well as in gneiss and schist, it can be weathered into alluvial deposits. Gem-quality specimens come from Myanmar, Brazil, Kenya, Madagascar, Mozambique and Montana. India, Australia, and some U.S. locations boast alluvial deposits. The hardness of this mineral varies according to the direction of cleavage with an increase in hardness perpendicular to the cleavage direction.
Gemological Information for Kyanite
| Color: | Light to Dark Blue, Colorless, Gray or Brown (Banded with Blue) |
| Crystal Structure: | Triclinic |
| Refractive Index: | 1.716 – 1.731 |
| Durability: | Poor |
| Hardness: | 6 to 7.5 or 4 to 5 (Depending on Angle) |
| Family: | |
| Similar Stones: | Idocrase, Epidote, Sapphire, Tanzanite, Spinel |
| Treatments: | None Known at this Time |
| Country of Origin: | U.S., Russia, India, Pakistan, Myanmar, Kenya, Brazil |
Kyanite Care
| Ultrasonic Cleaning: | Never |
| Steam Cleaning: | Never |
| Warm Soapy Water: | Safe |
| Chemical Attack: | Not Attacked |
| Light Sensitivity: | Stable |
| Heat Sensitivity: | Sensitive |
Sources
- Gem Reference Guide, Los Angeles: Gemological Institute of America, 1988.
- Hall, Cally. Gemstones, Smithsonian Handbooks. London, DK Penguin Random House, 2021.