mineral

Blue Kyanite

Kyanite (Al2SiO5)

AI-generated identification · may be incorrect

Hardness varies significantly depending on the direction: 4.5 to 5.5 parallel to the length, and 6.5 to 7 across the width. Color ranges from light to dark blue, sometimes green, grey, or white. Luster is vitreous to pearly. Crystal structure is triclinic, typically forming long, blade-like crystals.

Identified July 29, 2026More mineral →

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Physical properties

Formation & geological history

Forms primarily in aluminum-rich metamorphic rocks, such as gneiss and schist, resulting from the high-pressure alteration of clay minerals during regional metamorphism.

Uses & applications

Used in the manufacture of refractory products, ceramics, electrical insulators, brake linings, and occasionally cut into cabochons or beads for jewelry.

Geological facts

Kyanite is one of the best examples of anisotropy in minerals, exhibiting completely different hardness values depending on the direction the scratch test is performed.

Field identification & locations

Easily identified by its distinctive blade-like crystal habit, prominent blue coloration, and variable hardness along different axes. Found in Brazil, USA, Switzerland, and Russia.