Medical Dictionary
Main Entry:
Mohs' scale Pronunciation:
'mOz-, 'mOs-, 'mO-s&z- Function:
noun 1 : a scale of hardness for minerals in which 1 represents thehardness of talc; 2, gypsum; 3, calcite; 4, fluorite; 5, apatite; 6, orthoclase; 7, quartz; 8, topaz; 9, corundum; and 10, diamond
2 : a revised and expanded version of theoriginal Mohs' scale which provides finer distinctions between the harder materials and in which 1 represents the hardness of talc; 2, gypsum; 3, calcite; 4, fluorite; 5, apatite; 6, orthoclase; 7,vitreous pure silica; 8, quartz; 9, topaz; 10, garnet; 11, fused zirconium oxide; 12, fused alumina; 13, silicon carbide; 14, boron carbide; and 15, diamond
Mohs /'mOs,/ Friedrich (1773–1839), German mineralogist. Mohs's chief scientific contribution was establishing systematic mineralogy on a new basis. He was placed in charge of several importantmineral collections, of which he later published systematic descriptions. In the early 1820s he developed a new method of mineral classification that focused on the arrangements of minerals in crystalsystems based on external symmetry. In 1812 he introduced the Mohs' scale of hardness for minerals. By the 1820s the scale had been widely adopted by other mineralogists.
