Moh's scale is a relative hardness scale for minerals rating them from 1 to 10. The values are not proportional. Diamond is rated a 10 and is the hardest mineral and Talc is rated 1 and is the softest.

Moh's Scale of Relative Hardness
1.	Talc
2	Gypsum
3.	Calcite
4.	Fluorite
5.	Apatite
6.	Orthoclase Feldspar
7.	Quartz
8.	Topaz
9.	Corundum
10.	Diamond