The mohs scale of hardness

The Mohs scale of hardness is a measure used to determine the scratch resistance of minerals. It was created by German geologist Friedrich Mohs in 1812 and is one of the most widely used and well known scales of mineral hardness.

The Mohs scale contains ten minerals that are arranged according to their relative hardness from softest to hardest. Each mineral on the scale is harder than the one below it and can scratch all the minerals on the scale below it. Here is a list of the minerals on the Mohs scale of hardness in order from softest to hardest: talc, rock salt, calcite, fluorite, apatite, feldspar, quartz, topaz, corundum and diamond.

Source: klenota.com