20 of 20 Items
20 of 20 Items
Kyanite is a unique mineral. It's anisotropic meaning it has two different hardness due to slight variations in its crystals. When it's cut parallel to its long axis, the hardness of Kyanite can range from 4 to 4.5, but when cut perpendicularly, its hardness ranges from 6 to 7. Kyanite is also a polymorph with two other minerals: Andalusite and Sillimanite. A Polymorph mineral shares the same chemistry as another but, has a different crystal structure.