Mohs scale of hardness
Mohs' scale of hardness The scale is not regular. Diamond, the hardest known natural substance, is 90 times harder than corundum.
Mineral | Hardness | Simple hardness test |
---|---|---|
Talc | 1.0 | Crushed by fingernail |
Gypsum | 2.0 | Scratched by fingernail |
Calcite | 3.0 | Scratched by copper coin |
Fluorspar | 4.0 | Scratched by glass |
Apatite | 5.0 | Scratched by knife blade |
Feldspar | 6.0 | Scratched by quartz |
Quartz | 7.0 | Scratched by steel file |
Topaz | 8.0 | Scratched by corundum |
Corundum | 9.0 | Scratched by diamond |
Diamond | 10.0 | ―― |
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