The Mohs Scale of Mineral Hardness
The Mohs Scale is a scale that measures hardness of solid objects, mainly rocks and minerals. A mineralogist named Friedrich Mohs invented it in 1812.
The original scale is below:
| Mineral Name | Hardness |
|---|---|
| Talc | 1 |
| Gypsum | 2 |
| Calcite | 3 |
| Fluorite | 4 |
| Apatite | 5 |
| Orthoclase Feldspar | 6 |
| Quartz | 7 |
| Topaz | 8 |
| Corundum | 9 |
| Diamond | 10 |
Diagnostic tools:
| Mineral Name | Hardness |
|---|---|
| Fingernail | 2.5 |
| Copper Penny | 3 |
| Glass plate or Steel knife | 5.5 |
| Steel file | 6.5 |
Reference[]
http://www.oakton.edu/user/4/billtong/eas100lab/hardness.htm