Feldspar, SiO2 % : 66% - 69%

Feldspar is the name of a group of rock-forming minerals which make up as 60% of the Earth’s crust, Feldspar crystallize from magma in both intrusive igneous rocks, and they can also occur as compact minerals, as veins, and are also present in many types of metamorphic rock. It is used in making the body composition of several types of procelain, china and earthenware and also in the preparation of glazes and enamel as an important ingredient in the glass sand batch as a bonding agent in the manufacture of bonded abrasives like wheels and discs of garnet, corundum, emery etc.