Talc Talc Talc or talcum is a clay mineral composed of hydrated magnesium silicate with the chemical formula HMg(SiO) or MgSiO(OH). In loose form, it is (in ratio with or without corn starch) one of the most widely used substances known as baby powder. It occurs as foliated to fibrous masses, and in an exceptionally rare crystal form. It has a perfect basal cleavage, and the folia are not elastic, although slightly flexible. The Mohs scale of mineral hardness, based on scratch hardness comparison, defines value 1 as the hardness of talc. Talc can easily be scratched by a fingernail. Talc
Mineral Revolution and formed the basis of the apartheid system, which dominated South African society for a century. The Mineral Revolution began with the discovery of diamonds at the town of Kimberley in 1867. The discovery of diamonds led to a rush of prospectors descending on the town, whose population skyrocketed as increasing numbers of prospectors arrived to seek their fortune. As more diggers arrived in Kimberley, diamond-mining increased in scale, focusing in open-pit mining of three main sites. As surface deposits of diamonds were excavated, deeper pits had to be dug, propelling the Mineral Revolution into a new phase. To excavate