MOHS SCALE OF HARDNESS
A German mineralogist, Fredrich Mohs invented a scale of relative mineral hardness that has become known as the Mohs scale. Until this day, this scale has been a valuable tool in identifying minerals since 1812.
The 10-point scale of mineral hardness. One the Mohs scale of relative hardness, a diamond is rated as 10. This means that it is the hardest mineral known to man. Only a mineral that is the same hardness grade can scratch the mineral. Sapphires for example are graded 9 on the Moh’s scale which means that only another Sapphire or a diamond (because the diamond is harder) can scratch a Sapphire. Yet, Sapphires cannot scratch a diamond because it is softer.
Mohs 10-point scale of mineral hardness table:
| Hardness (from hard to soft) | Mineral |
|---|---|
| 10 | Diamond |
| 9 | Sapphire, Corundum and Ruby |
| 8 | Emerald, Aquamarine, Topaz, Beryl and Hardened Steel |
| 7 | Quarts, Amethyst, Citrine and Agate |
| 6.5 | Tanzanite, Steel file, Iron Pyrite, Glass and Vitreous Pure Silca |
| 6 | Orthoclase, Titanium and Spectrolite |
| 5 | Apatite |
| 4.5 | Platinum and Iron |
| 4 | Fluorite |
| 3 | Calcite and Copper Coin |
| 2.5 | Pure 24K Gold, Silver and Aluminium |
| 2 | Gypsum |
| 1 | Talc |
