When we talk about hardness in a colored stone we are talking about its resistance to scratches. We need to think about the hardness of a stone when we decide what type of jewelry the stone will best be used for. The Mohs scale was created by a professor from Germany named Friedrich Mohs. Stones are rated from 1 to 10 with 10 being the hardest. Diamond has a rating of 10 and is harder than any other gemstone. Rubies and sapphires which are both corundum have a rating of 9 and they are fine to be used as stones in rings. Those with a rating of under 7 will wear if used in a ring or a bracelet. That’s not to say you can’t do it but that you should wear them carefully.
Mohs Scale Examples
10. Diamond
9. Corundum
8. Topaz
7. Quartz
6. Orthoclase feldspar
5. Apatite
4. Fluorite
3. Calcite
2. Gypsum
1. Talc
