Element |
Hardness on Mohs scale |
Caesium |
0.2 |
Rubidium |
0.3 |
Potassium |
0.4 |
Sodium |
0.5 |
Carbon graphite |
0.5 |
White phosphorus |
0.5 |
Lithium |
0.6 |
Indium |
1.2 |
Thallium |
1.2 |
Barium |
1.25 |
Strontium |
1.5 |
Mercury |
1.5 |
Gallium |
1.5 |
Tin |
1.5 |
Lead |
1.5 |
Calcium |
1.75 |
Cadmium |
2.0 |
Sulfur |
2.0 |
Selenium |
2.0 |
Bismuth |
2.3 |
Tellurium |
2.3 |
Magnesium |
2.5 |
Cerium |
2.5 |
Lanthanum |
2.5 |
Silver |
2.5 |
Gold |
2.5 |
Zinc |
2.5 |
Aluminium |
2.8 |
Copper |
3.0 |
Antimony |
3.2 |
Platinum |
3.5 |
Arsenic |
3.5 |
Iron |
4.0 |
Nickel |
4.0 |
Palladium |
4.8 |
Zirconium |
5.0 |
Cobalt |
5.0 |
Beryllium |
5.5 |
Hafnium |
5.5 |
Molybdenum |
5.5 |
Uranium |
6.0 |
Titanium |
6.0 |
Niobium |
6.0 |
Manganese |
6.0 |
Rhodium |
6.0 |
Germanium |
6.0 |
Ruthenium |
6.5 |
Tantalum |
6.5 |
Ruthenium |
6.5 |
Iridium |
6.5 |
Vanadium |
7.0 |
Rhenium |
7.0 |
Osmium |
7.0 |
Silicon |
7.0 |
Tungsten |
7.5 |
Chromium |
8.5 |
Boron |
9.3 |
Carbon diamond |
10.0 |
This list was taken from various sources.