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
Frederic E. Mohs Frederic E. Mohs Frederic Edward Mohs (1 March 1910 – 2 July 2002), a physician and general surgeon, developed the Mohs micrographic surgery (MMS) technique in 1938 to remove skin cancer lesions while still a medical student at the University of Wisconsin–Madison. The Mohs procedure is considered the best method for treating certain types of skin cancer, because it has very high cure rates for even high-risk lesions, combined with maximal preservation of healthy tissues. Mohs was born in Burlington, Wisconsin. His father died when he was 3 months old, and the family moved to Madison, where his mother ran