The Mohs' Hardness Scale is an internationally recognised scale, used by jewellers and gemologists for measuring the hardness of a crystal, stone or mineral. It is measured based on whether or not a material can be scratched easily and can scratch another crystal easily, therefore it is not a perfect guide for how strong and durable a crystal is but is an excellent place to start. Similarly it is not a perfect indicator of a crystals water resistance, but can be a great clue as to whether a crystal is porous and water-soluble or hard and insoluble. The reason the Mohs' Scale is not a perfect guide but is a really great starting point is that, while generally speaking all the higher numbered stones are tough, hard to break and 'waterproof' to a certain extent, this is not always the case. Some that are low on the list might be water resistant or hard to break despite being scratchable while others might be hard but brittle or strong but water soluble. Not only is the Mohs' Scale handy when choosing and cleaning a crystal but it's also the best measure of if you can store a particular crystal loose with other stones or if it will be easily scratched by others. 

Below are the official classifications and underneath, further examples. This information can also be found with each shop listing and in our Crystal Archive!

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1. Talc 2. Gypsum 3. Calcite 4. Fluorite 5. Apatite 6. Orthoclase 7. Quartz 8. Topaz 9. Corundum 10. Diamond

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Other low on the list materials include Gold, Muscovite and Stichtite.

Other high on the list materials include Rubies, Emeralds and Sapphires. 

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