Kyanite
Image: Robert M. Lavinsky (CC BY-SA 3.0)
Mineral NameKyanite
Chemical FormulaAl2SiO5
Mohs Hardness6
Crystal Systemtriclinic
Lustervitreous
Streak Colorwhite
Cleavageperfect on {100}, good on {010}
Fracturesplintery
Specific Gravity3.6
Colorsblue, white, gray, green
Transparencytransparent
Type LocalityLitchfield, Litchfield County, Connecticut, USA
Mineral Groupsilicates
Usesrefractory materials, ceramics, abrasives, gemstone
Associated Mineralsquartz, muscovite, garnet, staurolite, andalusite, sillimanite
Raritycommon
Description
This image displays a cluster of elongated, bladed blue kyanite crystals, exhibiting a vitreous luster. The crystals are well-formed and show characteristic parallel growth.
Geological Context
Kyanite is a metamorphic mineral formed under high-pressure, low-to-moderate temperature conditions, typically found in schists and gneisses. It is an indicator mineral for regional metamorphism.
