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1·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.

钻石，是对莫氏硬度标度10，这意味着他们不仅是最困难的矿物质，但它们实际上是地球上最困难的实质内容。

3·Sapphire has a hardness of 9 on the Mohs scale and is also extremely tough.

蓝宝石具有硬度大、9月的层数也非常强硬。