Mohs Scale

(redirected from Hardness scale)
Also found in: Dictionary, Thesaurus, Medical.
Related to Hardness scale: Vickers hardness scale

Mohs scale

[′mōz ‚skāl]
An empirical scale consisting of 10 minerals with reference to which the hardness of all other minerals is measured; it includes, from softest (designated 1) to hardest (10): talc, gypsum, calcite, fluorite, apatite, orthoclase, quartz, topaz, corundum, and diamond.

Mohs’ Scale


a ten-point scale for measuring the relative hardness of minerals. Proposed by the German scientist F. Mohs in 1811, the scale (see Table 1) comprises ten standards of hardness.

Table 1. Mohs’ scale of hardness

The relative hardness is determined by scratching the surface of the test specimen with a standard of the Mohs’ scale. If, for example, the standard apatite, having a hardness of 5, scratches the specimen and the specimen itself leaves a mark on the surface of fluorite, the standard with a hardness of 4, then the hardness of the mineral being tested is approximately 4.5. Mohs’ scale facilitates the rapid identification of minerals.

References in periodicals archive ?
2) The Mohs hardness scale goes from 1, for the softest minerals, to 10, for the hardest.
The Russack hardness scale for bricks, as shown below, ranges from 0 to 10 on the scale; the higher the number, the more durable the brick.
Its numerical value is a function of the hardness scale used for comparison and the method of measurement employed.
This resistance, which also plays an important role in wear analysis, is generally indicated by reference to standard hardness scale.
The NeoV Optic Filter glass reaches a phenomenal 6H on the hardness scale - a measurement about equal to that of steel.
Users can choose from universal models that can run any popular hardness scale test (Vickers, micro-Vickers, Brinell, Rockwell, superficial Rockwell, Knoop, HBT or HVT) or method-specific units.
Medalist MD-447 is so soft that it cannot be measured accurately on the Shore A hardness scale used for other Medalist TPEs, the softest of which has a rating of 5A.
In some areas, rock was 31,000 psi on the hardness scale.
PREDICT: The Mohs hardness scale ** ranks 10 minerals from softest to hardest.
Establishing a world-wide unified Rockwell hardness scale with metrological traceability, Metrologia 34, 331-342 (1997).
0008" thick and has a hardness of 3200 to 3800 on the Vickers hardness scale.