mineral
Kyanite
Kyanite (Al2SiO5)
Hardness: 4.5 to 7 (anisotropic), Color: Blue, Luster: Vitreous to pearly, Crystal structure: Triclinic, Cleavage: Perfect in one direction, Specific gravity: 3.53 to 3.67
- Hardness
- 4
Identified More mineral →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 4.5 to 7 (anisotropic), Color: Blue, Luster: Vitreous to pearly, Crystal structure: Triclinic, Cleavage: Perfect in one direction, Specific gravity: 3.53 to 3.67
Formation & geological history
Formed through the regional metamorphism of clay-rich sedimentary rocks at high pressure. Usually found in mica schists and gneisses.
Uses & applications
Used in the manufacturing of refractory materials (ceramics, bricks), abrasive tools, and occasionally as a gemstone for jewelry.
Geological facts
Kyanite is unique because it displays varying hardness depending on the crystal axis: hardness of 4.5 parallel to the length and 7.0 perpendicular to it.
Field identification & locations
Identify in the field by its distinct bladed crystal habit and blue color. Common in metamorphic belts; collectors should look for high-grade metamorphic terrain.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Nephrite Jade
Nephrite
Mineral/Rock
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety often found as a river rock)
Metamorphic Rock
![Green Apatite on Albite (Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]) — mineral](https://media.rockidentification.com/2391a63f-fb20-47d5-af9a-2035851eb32e-thumbnail.jpg)
Green Apatite on Albite
Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]
mineral
Epidote
Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)
mineral