Kyanite, also Cyanite, Disthene or Sapparite is a common mineral from the mineral class of the "Silicates and germanates". It crystallizes in the triclinic crystal system with the chemical composition Al2[O|SiO4], so chemically it is an aluminium silicate. Structurally, it belongs to the island silicates.

Kyanite mainly develops prismatic to tabular crystals with a glass-like sheen on the surface, but also occurs in the form of fibrous or granular to massive mineral aggregates. In its pure form, kyanite is colorless and transparent. However, it can also appear white due to multiple light refractions caused by lattice defects or polycrystalline formation and can take on a light to dark blue, blue-violet, greenish to brownish and rarely reddish color due to foreign impurities, whereby the transparency decreases accordingly.