Friedrich Mohs, a German mineralogist, discovered the hardness scale in 1812. He selected ten minerals of distinctly different hardness that ranged from a very soft mineral (talc) to a very hard mineral (diamond). With the exception of diamond, the minerals are all relatively common, easy to obtain, and inexpensive.

See the accompanying table of the Mohs Hardness Scale minerals.

The Mohs Hardness Scale has been used by geologists and geology students for over 200 years. Millions of students have used the Mohs Hardness Test to identify minerals. It is surprising that such a simple test has been in use for over two centuries.