Mohs, Friedrich (1773-1839)

German mineralogist who 1812 devised Mohs' scale of minerals, classified in order of relative hardness. Mohs was born in the Saxon Hartz Mountains. He studied at Halle and at the Freiberg Mining Academy, and was appointed professor of mineralogy at Graz 1812, and later at Freiberg. He ended his career in Austria as professor at Vienna from 1826. Mohs achieved eminence for his system of the classification of minerals, dividing these into genera and species in the manner of Swedish botanist Linnaeus. Although recognized as useful, the strategy was widely criticized for failing to take sufficient account of chemical composition, and it is no longer used. He also classified crystals on the basis of the orientation of their axes.