Kyanite
Image: Didier Descouens (CC BY-SA 4.0)
Mineral NameKyanite
Chemical FormulaAl2SiO5
Mohs Hardness4.5
Crystal Systemtriclinic
Lustervitreous
Streak Colorwhite
CleavagePerfect on {100}, good on {010}
Fracturesplintery
Specific Gravity3.6
Colorsblue, white, gray, green, black
Transparencytransparent
Type LocalityMilka Danda (Milke Danda), Phakuwa, Sankhuwasabha District (Sankhuwa Sahba), Kosi Zone, Nepal
Mineral GroupSilicates
Usesjewelry, industrial, collector
Associated Mineralsquartz, feldspar, mica, garnet, staurolite
Rarityuncommon
Description
A faceted, oval-cut gemstone displaying a vibrant deep blue color with internal reflections, characteristic of gem-quality kyanite.
Geological Context
Kyanite is a metamorphic mineral typically found in high-pressure, low-to-moderate temperature metamorphic rocks such as schists and gneisses, often indicating regional metamorphism.
