| Hardness | Mineral |
| 1 | Talc |
| 2 | Gypsum |
| 3 | Calcite |
| 4 | Fluorite |
| 5 | Apatite |
| 6 | Orthoclase |
| 7 | Quartz |
| 8 | Topaz |
| 9 | Corundum |
| 10 | Diamond |
To identify minerals in the field even if you don't have a complete set of the minerals of hardness on hand (which most people won't), use the scratch-test to get a rough guess of hardness. All you need are these common materials:
| Hardness | Material |
| 2.2 | Your Fingernail |
| 3.2 | Copper Penny |
| 5.0 | Steel Nail |
| 5.5 | Glass |
| 7.0 | Streak Plate |