Mineral necessarily constant for all sides, which is a function of its structure; crystallographic weakness renders some directions softer than others. An example of this property exists in kyanite, which has a Mohs hardness of 5½ parallel to [001] but 7 parallel to [100]. The most common scale of measurement is the ordinal Mohs hardness scale. Defined by ten indicators, a mineral with a higher index scratches those below it. The scale ranges from talc, a phyllosilicate, to diamond, a carbon polymorph that is the hardest natural material. The scale is provided below: Lustre indicates how light reflects from the mineral's
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