It refers to Mohs hardness, which is scraped on the surface of the tested mineral with a pyramid-shaped Jin Gangzuan needle by scraping method. Traditionally, Mohs hardness is used in mineralogy or gemology. Named after F. Mons, he proposed 65,438+00 standard minerals for measuring the relative hardness of minerals. From small to large, it is divided into 10 grades: talc 1, gypsum 2, calcite 3, fluorite 4, apatite 5, orthoclase 6, quartz 7, topaz 8, corundum 9 and diamond 10.