mineral
Kyanite
Al2SiO5
AI-generated identification · may be incorrectHardness varies from 4.5 parallel to the blade and 6.5 perpendicular on the Mohs scale. Typically blue, gray, or green with a vitreous to pearly luster and a triclinic crystal system.
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Physical properties
Hardness varies from 4.5 parallel to the blade and 6.5 perpendicular on the Mohs scale. Typically blue, gray, or green with a vitreous to pearly luster and a triclinic crystal system.
Formation & geological history
Forms in aluminum-rich metamorphic rocks, primarily through the alteration of clay minerals during regional metamorphism of pelitic rocks.
Uses & applications
Used primarily in the manufacture of refractory products, ceramics, and occasionally cut into gemstones for jewelry.
Geological facts
Kyanite is well known for its highly anisotropic hardness, meaning it is significantly softer in one direction than another.
Field identification & locations
Identified by its bladed crystal habit, distinct directional hardness, and typical blue color. Found globally, notably in Brazil, Switzerland, and the USA.
