Barra do Salinas district, Barra do Salinas, Coronel Murta, Minas Gerais, Brazil

Al₂(SiO₄)O

Crystal System: triclinic
Colour: blue, white, light gray, green, rarely yellow, orange, pink
Lustre: vitreous, sub-vitreous, greasy, pearly
Habitus: bladed or tabular on {100}, elongated on [001]
Hardness: 5½ // [001], 7 // [100]
Cleavage: perfect on {100}, good on {010}
Fracture: splintery
Density: 3.67 g/cm³ 
Origin and geological occurrence: it occurs in gneisses, schists, and quartz veins. Its origin is related to moderately high-P regional metamorphism of Al-rich rocks. It is a polymorph of Al₂SiO₄O. The generally bluish colour is caused by Fe(II)-Fe(III) charge transfer.

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Samples:

9A.6 Kyanite Blue tabular elongated crystals in quartz. #neso soro silicates