About Moh's hardness scale


The Mohs scale of mineral hardness is based on the ability of one natural sample of mineral to scratch another mineral visibly. As the hardest known naturally occurring substance when the scale was designed, diamonds are at the top of the scale. The scale was created by the German geologist and mineralogist Friedrich Mohs in 1812 and is one of several common scales to define that hardness of a material.  

Hardness        

Substance or mineral

1

talc

1.5

tin, lead, graphite

2

calcium,  cadmium

2.5

Gold, Silver

3

copper

3.5

Platinum

4

iron, nickel

4–4.5

steel

5

tooth enamel, palladium

5.5

glass

6

titanium, Rhodium

6–7

opal, Peridot, tanzanite

7

quartz

7.5–8

Emerald, hardened steel

8

topaz, cubic zirconia

8.5

chromium

9

corundum

10

Diamond

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