| The MOHS Scale |
| Hardness Category |
MOHS Number |
Mineral Name |
Hardenss Test |
Mineral Image |
| Hard |
10 |
Diamond |
| No other mineral can scratch diamond. |
| Diamond can scratch all other minerals. |
|
 |
| 9 |
Corundum |
| Diamond can scratch Corundum (Rubies/Saphires). |
| Corunndum can scratch Topaz… |
|
 |
| 8 |
Topaz |
| Diamond and Corundum can scratch Topaz. |
| Topaz can scratch Quartz… |
|
 |
| 7 |
Quartz |
| Diamond, Corundum, and Topaz can scratch Quartz. |
| Quartz can scratch Feldspar… |
|
 |
| 6 |
Potassium Feldspar,
Plagioclase Feldspar |
| Diamond, Corundum, Topaz, and Quartz can scratch Feldspar.
Feldspar can scratch Apatite… |
Feldspar is the most common mineral in Earth’s crust. |
| There are two kinds of Feldspar, Potassium Feldspar (aka K-Spar) and Plagioclase Feldspar. |
Plagioclase Feldspar may be iridescent. Potassium Feldspar is usually salmon colored. |
|
 |
| Soft |
5 |
Apatite |
| Diamond, Corundum, Topaz, Quartz, and Feldspar can scratch Apatite. |
| Apatite can scratch Fluorite… |
|
 |
| 4 |
Fluorite |
| Diamond, Corundum, Topaz, Quartz, Feldspar, and Apatite can scratch Fluorite. |
| Fluorite can scratch Calcite… |
|
 |
| 3 |
Calcite |
| Diamond, Corundum, Topaz, Quartz, Feldspar, Apatite, and Fluorite can scratch Calcite. |
| Calcite can scratch Gypsum… |
|
 |
| 2 |
Gypsum |
| Diamond, Corundum, Topaz, Quartz, Feldspar, Apatite, Fluorite, and Calcite can scratch Gypsum. |
| Gypsum can scratch Talc… |
|
 |
| 1 |
Talc |
| Talc can’t scratch much of anything. |
|
 |
Tom's Rocks 