Mohs Hardness & Scratch Resistance

Compare minerals, absolute indentation values (Knoop), and scratch interactions using the classic Mohs mineral hardness scale.

Mohs Mineral scratch simulator
Mineral A (The Scratcher):
Absolute Knoop Hardness:100 kg/mm²
Scratches steel file and glass easily. Common grit.
Mineral B (The Target):
Absolute Knoop Hardness:21 kg/mm²
Scratched by steel pocketknife easily.
Scratch Resistance Comparison

Quartz scratches Fluorite!

With a Mohs hardness of 7, Quartz possesses higher scratch resistance than Fluorite (hardness 4). It will easily carve grooves into its surface.

Mineral A is ~4.8x harder on the absolute scale
Common scratch objects
FingernailH: 2.2
Copper Wire / PennyH: 3.2
Brass KeyH: 4
Pocketknife BladeH: 5.5
Window GlassH: 5.5
Steel FileH: 6.5
Tungsten CarbideH: 8.5
Mohs Scale Mineral Directory
1. TalcAbs: 1
2. GypsumAbs: 3
3. CalciteAbs: 9
4. FluoriteAbs: 21
5. ApatiteAbs: 48
6. Orthoclase FeldsparAbs: 72
7. QuartzAbs: 100
8. TopazAbs: 200
9. CorundumAbs: 400
10. DiamondAbs: 1500

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