MOHS Scale of Hardness
Mohs Scale of Hardness
| Hardness | Substance |
|---|---|
| 2.5 | Amber, Ivory, Shell |
| 3-4 | Pearl |
| 5 | Glass |
| 5.5-5 | Lapis, Lazuli |
| 5-6 | Opal, Turquoise |
| 6-6.5 | Sodalite |
| 6-7 | Onyx, Peridot, Quartz |
| 7 | Agate, Amethyst, Citrine, Prasiolite |
| 7-7.5 | Garnet, Tourmaline |
| 7.5 | Zircone |
| 7.5-8 | Aquamarine, Emerald |
| 8 | Topaz |
| 8.5 | Alexandrite |
| 9 | Ruby, Sapphire |
| 10 | Diamond |
| A hardness of 1 or 2 can be scratched with a fingernail, 3 to 4 scratched with a penny, 5-6 scratched with a knife blade, 6 scratched with a stepl file, 7 to 10 can scratch glass. | |