When looking for gemstones for jewellery, engagement rings or othewise, you may see or hear your jeweller or your jewellers website mention Moh’s Hardness Scale.
The Moh’s Hardness Scale is a relative system based on 10 different minerals and gemstones used as a reference for how easily specific gemstones scratch. 1 is the easiest to scratch and a 10 is the most difficult. Diamonds are a 10.
The concept is if you have a stone of unknown hardness, and reference mineral #5 can scratch it, then the hardness of your gem is less than or equal to a Mohs hardness of 5. Similarly, if your gem cannot be scratched by reference mineral #5, then its hardness is greater than or equal to a Mohs hardness of 5.
Moh’s Scale is the most commonly used system to rate the hardness of gemstones. Anything with a rating of or above 7 is what is most commonly used in jewellery today.
Diamonds are the hardest minerals on earth; they are 4-5 times harder than corundum, the family of sapphires and rubies, which are rated a 9 on the scale. Understandably, this is why diamonds are so desirable for engagement rings.
|9||Corundum (Sapphire & Ruby)|
|8||Topaz, Emerald, Aquamarine||Masonry drill bit (8.5)|
|7||Quartz (Amethyst, Citrine and Agate)|
|3||Calcite||Copper coin (3.5)|