The Mohs Scale of Mineral Hardness

The Mohs scale of mineral hardness characterizes the scratch resistance of various minerals, through the ability of a harder material to scratch a softer one and not be scratched by it. While the varying hardness of stones was likely first explored around 300 BCE, German mineralogist Friedrich Mohs devised his scale in 1812. It uses 10 standards ranging from talc, the softest, with a value of 1, to diamond, the hardest, with a value of 10. Where does a fingernail fall on the Mohs scale? More… Discuss