Kyanite crystallizes in the form of twisted fibrous structures, masses, columnar aggregates, radiating groups, and long bladed crystals which are either twisted or straight. The colour range includes grey, black, and blue with white, greem, colourless, and both yellow and pink (due to inclusions of other minerals). Kyanite was first reported in 1789 by A.G. Werner and was named from the Greek word meaning "blue", in reference to the primary colour of the mineral.
The chemical composition is:Al2SiO5
Hardness 4 - 5