What is mineral or gemstone Mohs Hardness Scale ( Mohs scale ) with picture and infographic

What is mineral gemstone mohs scale hardness banner

We talked a a lot about mohs hardness scale, so what is mohs scale ?

The Mohs Hardness Scale is a tool or ways people used as a convenient way to help identify minerals by their hardness. The scale is named for its creator, the German geologist and mineralogist Friedrich Mohs.

German geologist and mineralogist Friedrich Mohs photo picture

 

The way they do that is they would measure the mineral’s relative resistance to scratching, measured by scratching them against another substance of known hardness.

Hardness is the term we use to describe the resistance of a material to being scratched. The test is conducted by placing a sharp point of one specimen on an unmarked surface of another specimen and attempting to produce a scratch.

So basically they will try so scratch the surface of one mineral with the other mineral.

The softer mineral will not be able to left the scratch mark on the harder mineral.

The the two minerals have the same hardness, they will usually left very light to no mark to one another, and will be difficult to decide the hardness to untrained person.

Then they will put the numerical values to this physical property. By that number, minerals are ranked along the Mohs scale, which is composed of 10 minerals that have been given arbitrary hardness values.

AR Signature Gem Mineral Mohs scale 1 -10 talc to diamond

Some people, sometime, use ordinary household item to quickly determine the hardness of a mineral. Although this can work sometime, the result may somewhat vary because the material of the household item might be different one to another.

The most common ordinary item used in most "guideline" found in internet and our comment about them :

    • Penny coin : Pennies are not made with copper anymore, so find a real copper to measure the hardness.

    Cooper Mineral in raw form by Almaciga

    Above is picture of raw cooper

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        • Glass : well, the hardness of glass in this modern days are so vary. It can be between 4 to 7.5 maybe more. But you will be able to scratch glass with mineral in mohs scale 7 and above. so Quartz, Topaz, Corundum, and Diamond.
              • Knife : all knife geek will know that knife hardness will vary depending a lot of thing, even with the same material, the process to tamper it will have effect on it's hardness. But Normal knife will be able to scratch gem until mohs scale 6.
                various knife for mohs scale blog

                As you can see, knife made with various type of metal, each have different hardness, so it's hard to tell accurately their hardness compared to mohs scale

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                • Fingernail : With fingernail you can easily scratch gem in mohs scale 1 - 2, so Talc and Gypsum, but will hardly scratch mineral in mohs scale 3 and above.
                • Masonary drill bit : is drill bit that designed for drilling into tough materials such as stone, block or concrete. Again, drill bit made from so many different material, but most of them will be able to scratch topaz, and maybe corundum.

                So the question, are there mineral that are harder than diamond? or maybe softer than talc ?

                Well, there are, but unless you work as person who specialist at mineral, it is highly unlikely you will encounter one.

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