mineral
Blue kyanite crystal fragment
Kyanite — Al₂SiO₅
AI-generated identification · may be incorrectBlue-gray, bladed crystal with a vitreous to pearly luster and lengthwise striations. Mohs hardness is strongly directional: about 4.5–5.5 across the blade and 6.5–7 along it; triclinic crystal system, with distinct cleavage.
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Physical properties
Blue-gray, bladed crystal with a vitreous to pearly luster and lengthwise striations. Mohs hardness is strongly directional: about 4.5–5.5 across the blade and 6.5–7 along it; triclinic crystal system, with distinct cleavage.
Formation & geological history
Forms chiefly during regional metamorphism of aluminum-rich sediments, commonly in schist and gneiss. Kyanite-bearing rocks occur across a wide range of geological ages.
Uses & applications
Used as a source of alumina in refractory ceramics and kiln products; attractive crystals are collected and occasionally cut as gemstones.
Geological facts
Kyanite’s unusual directional hardness can make cutting and polishing challenging.
Field identification & locations
Identify it by its blue, flattened, striated blades and variable hardness; common sources include Brazil, Nepal, India, and the United States. The image alone cannot confirm the identification or locality.
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Undetermined; the image is too blurry for reliable identification
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