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
Mohs surgery The fault of the surgeon is failure to understand pathology laboratory methods, and failure to follow the standard of care for adequate surgical margin. Usually, the cure rate using standard bread loafing is very low for narrow surgical margin and a large tumor, and very high for large margins on small tumors. Some dermatologists, oncologists and health economists say that Mohs surgery is overused, because it is highly profitable. Dermatologists may perform the surgery on areas of the skin where it is not necessary, or perform unwanted cosmetic surgery. The incidence of Mohs surgery increased by more than 400% between