Human teeth are harder than gold but softer than pyrite, according to the Mohs Hardness Scale, which categorizes how easily minerals scratch.
根据莫氏硬度表，人类牙齿的硬度比黄金大但比黄铁矿小。
2
Diamonds are a 10 on the MOHS Hardness Scale which means that they are not only the hardest mineral, but they are actually the hardest substance on earth.