Friedrich Mohs harder. This became the basis of the hardness scale developed by Mohs. The hardest mineral, diamond was given a value of 10 and softer minerals such as talc were given the very low value of 1 (unity). Other minerals were given intermediate values, depending on their ability to scratch another mineral in the scale. Thus gypsum was given the value 2 because it will scratch talc crystals, and calcite the value 3 because it will scratch gypsum. Minerals are also now classified by chemical characteristics, but the physical properties are still useful in field examination. In 1812, Mohs became a
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