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Products -> Moh's Hardness Scale

One of the major factors which govern the choice and design of size reduction machines, air classifiers, mixers and dryers, etc. is the hardness of the material to be processed.

As general rule, the hardness is defined in accordance with Moh's scale of hardness, which divided into 10 grades of Hardness.

Hardness 1 - 3 = Soft
Hardness 3.5 - 5 = Medium Hard
Hardness 5 - 10 = Hard

Material	Hardness	Material	Hardness
Anhydrate	3-3.5	Kaolin	2
Anthracite	2-2.5	Chalk/Limestone	3
Apatite	5	Corundum	9
Asbestos	3	Magnesite	4-4.5
Baryte	3-3.5	Magnetite	5.5-6
Basalt	8	Marble	3
Bentonite	1	Pitchblende	4-6
Boron Carbide	9.5	Pyrite	6-6.5
Boron Notride, cubic	9.37	Quartz	7
Calcite	3	Red Iron Ore	5.5-6.5
Diamond	10	Rhodonite	5-6.5
Dolomite	3.5-4	Rutile	6-6.5
Siderite	4-4.5	Sulfur	1.5-2
Colored Clays	1-2	Pearl White	3-3.5
Feldspar	6	Silicon Carbide	9
Fluorite	4	Steatite	1
Gypsum	1.5-2	Rock Salt	2
Mica	2.5	Talcum	1
Garnet	6.5-7.5	Zirconium Oxide	8.5
Granite	7	Zircon Sand	7.5
Graphite	1	Tungsten Carbide	8.5