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 2004 and 2014. In a sample of 100 Mohs surgeries, the cost ranged from US$474 to USUS$7,594, with the higher costs for hospital-based physicians. In 2010, hospital-based dermatologists who did Mohs surgery were paid US$586,083, according to Becker's Hospital Review. When the surgery is performed in different steps by different specialists, each specialist can bill for his or her own procedure, such as the surgery itself, closing the wound, anesthesiology, and facilities fees. This can total more than US$25,000 for a single procedure. Originally, Mohs used a chemical paste (an escharotic agent) to cauterize and kill the tissue. It was