Black Kyanite Rough Boxed

Kyanite is rich in Aluminium and is typically blue colour but varieties can be found in orange, black, white or green. 
This stone forms in sharp bladelike shapes and can be found mainly in Brazil and Africa.
Its name comes from the same origin as the colour cyan, being derived from the Ancient Greek word κύανος.
Other names for this mineral are disthene or cyanite.