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 tremendous cure rates for primary basal-cell carcinoma. Studies by Smeet, et al. showing a Mohs cure rate of about 95%, and another study in Sweden showing Mohs cure rate of about 94%. Some of Mohs' data revealed a cure rate as low as 96%, but these were often very large tumors, previously treated by other modalities. Some authors claim that their 5-year cure rate for primary basal-cell cancer exceeded 99% while other noted more conservative cure rate of 97%. The quoted cure rate for Mohs surgery on previously treated basal-cell cancer is about 94%. Reasons for variations in the cure