Hardness is one of the main considerations when shopping for a gemstone. Usually the term hardness is meant to convey how well a gemstone resists abrasion. One of the ways that gemologists determine the hardness of gemstones is through the use of Moh’s hardness scale.
The Moh’s hardness scale was created by a German mineralogist Friedrich Mohs, it mainly measures the scratch resistance of various minerals, through the ability of a harder material to scratch or abrade a softer mineral.
There are ten materials on the Moh’s scale and they are listed from soft to hard, besides their rank, they are given an absolute hardness score. For instance, talc is the softest mineral and has an absolute hardness score of 1, Diamonds are the hardest material known to man and have an absolute hardness score of 15,000. Here is a list of minerals from softest to hardest along with their absolute hardness number:
- Talc absolute hardness 1
- Gypsum absolute hardness 2
- Calcite absolute hardness 9
- Fluorite absolute hardness 21
- Apatite absolute hardness 48
- Orthoclase Feldspar absolute hardness 72
- Quartz absolute hardness 100
- Topaz absolute hardness 200
- Corundum absolute hardness 400
- Diamond absolute hardness 1500
Usually hardness is a good indicator to identify which gemstones are durable and easily worn on a day to day basis. A less hard gemstone will either need to be protected with a resin or worn less frequently, while gemstones with a high hardenss can be worn daily with no problems at all.