What is Mohs scale?
The Dictionary of Gem and Gemology defines Mohs scale as: “The most commonly used scale of relative hardness of minerals. – diamond 10, corundum 9, topaz 8, quartz 7, orthoclase feldspar 6, apatite 5, fluorite 4, calcite 3, gypsum 2, talc 1. Division are not equal, minerals representing various harnesses having been chosen arbitrarily by the mineralogist F. Mohs. The difference between 9 and 8 is considerably greater than between the lower numbers and between 9 an 10 is greater than between 9 and 1.
