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|
|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|
|4.5||Platinum and Iron|
|3||Calcite and Copper Coin|
|2.5||Pure 24K Gold, Silver and Aluminium|