Mohs Hardness Scale

Mohs Hardness Scale

Mohs hardness is measured on a scale from 1 to 10. The scale was made about 200 years ago by Friedrich Mohs. Softer minerals have low numbers and harder minerals have high numbers.

The Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. It was created in 1812 by the German mineralogist Friedrich Mohs and is one of several definitions of hardness in materials science. The scale is based on ten minerals. Diamond, the hardest known naturally occurring substance, is at the top of the scale. The hardness of a material is measured against the scale by finding the hardest material that the given material can scratch, and/or the softest material that can scratch the given material.

If some material is scratched by a fingernail but not by penny, its hardness on the Mohs scale would fall between the two. The Mohs scale is a purely ordinal scale. For example, the Densitron SAW and Projected Capacitive Touch screens are over 10 times harder than our standard Resistive Touch Screen.

The Mohs Hardness table to the right shows comparison with absolute hardness measured by a sclerometer of common materials.

Hardness	Reference Material	Absolute Hardness
1	Talc	1
2	Gypsum	2
2.5	Fingernail
3	Film to Glass Resistive Touch	9
3.5	Copper Penny
4	Fluorspar	21
4 - 4.5	Platinum
5	Tooth Enamel	48
5.5	Window Glass, Knife Blade
6	Pumice	72
6.5	Steel File
7	Quartz	100
7	5 Wire Resisitive Glass on Glass	100
7	Projected Capacitive Touch Screen	100
7	Surface Acoustic Wave Touch Screen	100
7.5	Hardened Steel File
8	Topaz	200
9	Tungsten Carbide	400
10	Diamond	1500

Densitron Corporation's customers come from a number of sectors, including medical, instrumentation, industrial equipment and automation, industrial machine controls, energy sector and telecommunication. Our client successes have traditionally focused on providing expert engineered cost effective solutions to the mid market. The information can be 1500used in assisting in making informed decisions regarding touch screen technology selection.