Moh’s Scale of Hardness
This scale represents the industry standard of gemstone hardness, with Diamonds being the hardest substance known to man. The Mohs scale of mineral hardness is a qualitative ordinal scale that characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. It was created in 1812 by the German geologist and mineralogist Friedrich Mohs and is one of several definitions of hardness in materials science, some of which are more quantitative.
Use this hardness scale as a guide to help you choose stones for jewelry designs.Be sure to use harder more durable stones where they have the most chance of impact while being worn. For such things as rings and bracelets you need to consider the hardness and fracturability of the gems, Stones like emerald although very hard can be fractured when they get impacted and it does not take much to cause a failure. The Moh’s hardness scale is a good tool to use along with other tools like the 4C’s in deciding which gems should be in your designs.