Kyanite

About

Kyanite Crystals Kyanite is an aluminum silicate mineral (Al₂SiO₅) crystallizing in the triclinic system. What makes kyanite remarkable is its anisotropic hardness — it measures 4.5 along the length of its blade-like crystals but 6.5–7 across the width, one of the most dramatic directional hardness variations in mineralogy. Its name comes from the Greek kyanos , meaning "deep blue." Major sources include Brazil, Nepal, Kenya, India, and the United States. Kyanite is a polymorph of both andalusite and sillimanite — all three share the same chemical composition but different crystal structures, each forming under distinct pressure and temperature conditions. For collectors, blue kyanite blades from Nepal and Brazil are particularly valued for vivid sapphire-blue color and sharp, elongated crystal habit. Orange kyanite from Tanzania is a more recent discovery and highly sought after for its rarity. Available forms include raw blade specimens and clusters, tumbled stones, palm stones, bracelets , and polished freeforms. For other blue minerals, see our lapis lazuli , sodalite , and labradorite collections. Browse crystal jewelry for kyanite pendants. Free shipping on orders $150+. Frequently Asked Questions What is kyanite? Kyanite is an aluminum silicate mineral (Al₂SiO₅) that forms blade-like crystals in metamorphic rocks. It is notable for having two different hardness values depending on direction — 4.5 along the crystal length and 6.5–7 across the width. Blue is the most common color, but kyanite also occurs in green, orange, and black. Why does kyanite have two different hardness values? Kyanite's anisotropic hardness is caused by its crystal structure — the bonds between atoms are weaker along the c-axis (length of the blade) and stronger perpendicular to it. This means you can scratch kyanite with a steel knife along its length but not across its width. Very few minerals show this degree of directional hardness variation. Where does kyanite come from? Nepal and