Mohs Scale​

 

The Mohs scale of mineral hardness is used as a convenient way to help identify minerals. A mineral's hardness is a measure of its relative resistance to scratching, measured by scratching the mineral against another substance of known hardness on the Mohs Scale.

 

The scale was created in 1822 by German geologist and mineralogist Friedrich Mohs. However, the method of comparing hardness has been used as far back as c. 300 BC, as mentioned by Theophrastus in his treatise On Stones.

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