Mineral Hardness - Mohs Scale
The Mohs qualitative ordinal scale characterizes the scratch resistance of various minerals.
The Mohs scale of mineral hardness characterizes the scratch resistance of various minerals or materials through the ability of a harder materials to scratch softer materials.
Mohs hardness | Typical Material |
---|---|
1 | Talc |
2 | Gypsum, Rock salt |
2.5 | Fingernail, pure gold, silver, aluminum |
3 | Calcspar (calcite), copper coin (penny) |
4 | Fluorspar (fluorite) |
4.5 | Platinum, iron |
5 | Apatite |
6 | Felspar, orthoclase, titanium, spectrolite |
6.5 | Steelfile, iron pyrite, glass, vitreous pure silica, streak plate |
7 | Quarts, amethyst, citrine, agate |
7.5 | Garnet |
8 | Topaz, hardened steel, beryl, emerald, aquamarine |
8.94 | Rock crystal quartz |
9 | African crystal corundum, ruby, sapphire |
9.03 | Fused alumina |
9.06 | Fused alumina (3.14% TiO2) |
9.09 | Tungsten carbid (13% cobalt) |
9.15 | Black silicon carbide |
9.32 | Boron carbide |
9.5 | Carborundum |
9.95 | Diamond, Congo clear white |
9.96 | Diamond, Congo yellow |
9.99 | Diamond, South American brown ballas |
10 | Diamond, South American brown bort |