mineral

Green Kyanite

Kyanite (Al2SiO5)

Hardness: 4.5-5.0 parallel to axes and 6.5-7.0 across axes (anisotropic). Color: Teal to deep forest green. Luster: Vitreous to pearly. Structure: Triclinic with bladed crystal habit. SG: 3.53 - 3.67.

Hardness: 4
Color: Teal to deep forest green
Luster: Vitreous to pearly

Identified March 15, 2026More mineral →

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Physical properties

Formation & geological history

Formed during regional metamorphism of clay-rich sedimentary rocks under high pressure. Green color is caused by trace amounts of chromium or iron. Typical of schist and gneiss environments.

Uses & applications

Used in the manufacturing of heat-resistant ceramics, spark plugs, and refractories. High-quality transparent specimens are used in jewelry (facet or cabochon) and raw blades are popular for metaphysical collecting.

Geological facts

Kyanite is one of the few minerals that displays a significant variation in hardness depending on which direction you scratch the crystal. Green kyanite is much rarer than blue kyanite and is primarily sourced from Brazil.

Field identification & locations

Identify by its distinct bladed/splintery appearance and varying hardness tests. Look for it in metamorphic belts like Minas Gerais, Brazil. Collectors should handle it carefully as it is brittle and prone to splintering.