By Chisom Ibemere
Kyanite is also called cyanite or disthene. It is an aluminosilicate mineral. It occurs in aluminium- rich metamorphic pegmatites and sedimentary rock. It exhibits anisotropism which is its variation in hardness in respect to the crystallographic direction. It has a range of pale to deep blue colour, gray, green or colourless, pink, rarely yellow.
Kyanite is used in the production of ceramics, abrasives. It is used in tracing metamorphic zones. It is used as a semi-precious stone. It has a wide usage in electronics, electrical insulators and abrasives.
Kyanite has a vitreous, sub vitreous, greasy and pearly lustre with a mohs hardness of 5.5-7 and specific gravity of 3.53-3.67. It has a Triclinic crystal system. Kyanite is a metamorphic silicate mineral which is known for its major bluish colour which is as a result of Iron in it. It has a perfect cleavage, brittle and transparent -transluscent.
Kyanite is named from the Greek word “kyanos” which means blue by Abraham Gottlieb in 1789. Cyanite, the french spelling of Kyanite had been used by mineralogists in the 19th and 20th centuries.
Kyanite occurs in gneiss, pegmatite, schist and quartz veins. It is found in sedimentary rocks as detrital grains. It is strong when stressed and low temperature and sufficiently high where muscorite, kaolinite containing aqueous aluminosilicates are replaced. It is found in association with Talc, mullite, Corundum, silimanite, Staurolite.
Kyanite is one of the natural mineral resources which had its deposits across the globe. It may be found in Nigeria, West Africa. Its deposits are found in Niger and Kaduna states of Nigeria. It has wide application in industries such as: it is used in semi-precious gemstone, in production of refractory products in rail road and automotive industries to make brake, shoes etc.