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Back to Tables and Charts
| Home Page | Abbreviated Contents | Customer Login | Quick Order / View Order | |
|---|---|---|---|---|
| Contact Us | Search | Indexes | Finish Order | |
| Hardnes Number | Original Scale | Modified Scale |
|---|---|---|
| 1 | Talc | Talc |
| 2 | Gypsum | Gypsum |
| 3 | Calcite | Calcite |
| 4 | Fluorite | Fluorite |
| 5 | Apatite | Apatite |
| 6 | Orthoclase | Orthoclase |
| 7 | Quartz | Vitreous Silica |
| 8 | Topaz | Quartz or Stellite |
| 9 | Corundum | Topaz |
| 10 | Diamond | Garnet |
| 11 | ............... | Fused Zirconia |
| 12 | ............... | Fused Alumina |
| 13 | ............... | Silicon Carbide |
| 14 | ............... | Boron Carbide |
| 15 | ............... | Diamond |
| Substance | Number | Substance | Number | |
|---|---|---|---|---|
| Agate | 6-7 | Indium | 1.2 | |
| Alabaster | 1.7 | Iridium | 6-6.5 | |
| Alum | 2-2.5 | Iridosmium | 7 | |
| Aluminum | 2-2.9 | Iron | 4-5 | |
| Alundum | 9+ | Kaolinite | 2.0-2.5 | |
| Amber | 2-2.5 | Lead | 1.5 | |
| Andalusite | 7.5 | Lithium | 0.6 | |
| Anthracite | 2.2 | Loess (0°) | 0.3 | |
| Antimony | 3.0-3.3 | Magnesium | 2.0 | |
| Apatite | 5 | Magnetite | 6 | |
| Aragonite | 3.5 | Manganese | 5.0 | |
| Arsenic | 3.5 | Marble | 3-4 | |
| Asbestos | 5 | Meerschaum | 2-3 | |
| Asphalt | 1-2 | Mica | 2.8 | |
| Augite | 6 | Opal | 4-6 | |
| Barite | 3.3 | Orthoclase | 6 | |
| Bell-metal | 4 | Osmium | 7.0 | |
| Beryl | 7.8 | Palladium | 4.8 | |
| Bismuth | 2.5 | Phosphorus | 0.5 | |
| Boric Acid | 3 | Phosphorbronze | 4 | |
| Boron | 9.5 | Platinum | 4.3 | |
| Brass | 3-4 | Plat-iridium | 6.5 | |
| Cadmium | 2.0 | Potassium | 0.5 | |
| Calamine | 5 | Pumice | 6 | |
| Calcite | 3 | Pyrite | 6.3 | |
| Calcium | 1.5 | Quartz | 7 | |
| Carbon | 10.0 | Rock Salt (halite) | 2 | |
| Carborundum | 9-10 | Ross' Metal | 2.5-3.0 | |
| Cesium | 0.2 | Rubidium | 0.3 | |
| Chromium | 9.0 | Ruthenium | 6.5 | |
| Copper | 2.5-3 | Selenium | 2.0 | |
| Corundum | 9 | Serpentine | 3-4 | |
| Diamond | 10 | Silicon | 7.0 | |
| Diatomaceous Earth | 1-1.5 | Silver | 2.5-4 | |
| Dolomite | 3.5-4 | Silver Chloride | 1.3 | |
| Emery | 7-9 | Sodium | 0.4 | |
| Feldspar | 6 | Steel | 5-8.5 | |
| Flint | 7 | Stibnite | 2 | |
| Fluorite | 4 | Strontium | 1.8 | |
| Galena | 2.5 | Sulfur | 1.5-2.5 | |
| Gallium | 1.5 | Talc | 1 | |
| Garnet | 6.5-7 | Tellurium | 2.3 | |
| Glass | 4.5-6.5 | Tin | 1.5-1.8 | |
| Gold | 2.5-3 | Topaz | 8 | |
| Graphite | 0.5-1 | Tourmaline | 7.3 | |
| Gypsum | 1.6-2 | Wax (0°) | 0.2 | |
| Hematite | 6 | Wood's Metal | 3 | |
| Hornblende | 5.5 | Zinc | 2.5 |
| Material | Formula | Mohs Value | Knoop Value |
|---|---|---|---|
| Talc | 3MgO-4SiO2-H2O | 1 | ... |
| Gypsum | CaSO4-2H2O | 2 | 32 |
| Cadmium | Cd | ... | 37 |
| Silver | Ag | ... | 60 |
| Zinc | Zn | ... | 119 |
| Calcite | CaCO3 | 3 | 135 |
| Fluorite | CaF2 | 4 | 163 |
| Copper | Cu | ... | 163 |
| Magnesia | MgO | ... | 370 |
| Apatite | CaF2-3Ca3(PO4)2 | 5 | 430 |
| Nickel | Ni | ... | 557 |
| Glass (soda lime) | ................................. | ... | 530 |
| Feldspar (orthoclase) | K2O-Al2O3-6SiO2 | 6 | 560 |
| Quartz | SiO2 | 7 | 820 |
| Chromium | Cr | ... | 935 |
| Zirconia | ZrO2 | ... | 1160 |
| Beryllia | BeO | ... | 1250 |
| Topaz | (AIF)2SiO4 | 8 | 1340 |
| Garnet | Al2O3-3FeO-3SiO2 | ... | 1360 |
| Tungsten Carbide Alloy | WC, Co | ... | 1400-1800 |
| Zirconium Boride | ZrB2 | ... | 1550 |
| Titanium Nitride | TiN | 9 | 1800 |
| Tungsten Carbide | WC | ... | 1880 |
| Tantalum Carbide | TaC | ... | 2000 |
| Zirconium Carbide | ZrC | ... | 2100 |
| Alumina | Al2O3 | ... | 2100 |
| Beryllium Carbide | Be2C | ... | 2410 |
| Titanium Carbide | TiC | ... | 2470 |
| Silicon Carbide | SiC | ... | 2480 |
| Aluminum Boride | AlB | ... | 2500 |
| Boron Carbide | B4C | ... | 2750 |
| Diamond | C | 10 | 7000 |