Kyanite
Image: Jarno from Rotterdam, Netherlands (CC BY 2.0)
Mineral NameKyanite
Chemical FormulaAl2SiO5
Mohs Hardness4.5
Crystal Systemtriclinic
Lustervitreous
Streak Colorwhite
Cleavageperfect on {100}, good on {010}
Fracturesplintery
Specific Gravity3.6
Colorsblue, grey, white
Transparencytransparent
Type LocalityWidespread in metamorphic terrains globally
Mineral Groupsilicates
Usesrefractory materials, ceramics, abrasives, gemstone, collector
Associated Mineralsquartz, muscovite, garnet, staurolite
Raritycommon
Description
This sample features bladed, blue-grey kyanite crystals intergrown with clear to milky white quartz, showcasing kyanite's characteristic elongated habit.
Geological Context
Kyanite is a metamorphic mineral formed under high-pressure, low-to-moderate temperature conditions, typically found in schists and gneisses derived from aluminous sedimentary rocks.
