Gem Hardness Scale
Mohs Scale: the most well know scale to measures relative hardness of minerals is know as the Mohs scales. Examples include:
- Diamond - 10
- Ruby & Sapphire - 9
- Topaz - 8
- Emerald - 7.5
- Feldspar - 6
- Apatite - 5
- Fluorite - 4
- Calcite - 3
- gypsum - 2
- Talc - 1
