hardness scale

Also found in: Dictionary, Thesaurus, Encyclopedia.
Related to hardness scale: Vickers hardness scale

hard·ness scale

a qualitative scale in which minerals are classified in order of their increasing hardness, based on the fact that the harder of two materials will scratch the softer and will not be scratched by it. The scale lists 15 substances: talc (1); gypsum (2); calcite (3); fluorite (4); apatite (5); orthoclase, periclase (6); vitreous pure silica (7); quartz, stellite (8); topaz (9); garnet (10); tantalum carbide, fused zirconia (11); fused alumina (12); silicon carbide (13); boron carbide (14); diamond (15).
See also: Mohs scale.
Farlex Partner Medical Dictionary © Farlex 2012

Mohs scale

A system that qualifies minerals according to hardness, ranging from talc (1) to diamond (15).
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.


Friedrich, German mineralogist, 1773-1839.
Mohs hardness number - a number on a mineralogic scale.
Mohs scale - a qualitative scale in which minerals are classified in order of their increasing hardness. Synonym(s): hardness scale
Medical Eponyms © Farlex 2012
References in periodicals archive ?
Moh's hardness scale is a comparative scale for minerals, whereby the softest mineral (talc) is placed at 1 and the hardest mineral (diamond) is placed at 10, with all other minerals ordered in between, according to their hardness.
In his Versuch einer Elementar-Methode zur naturhistorischen Bestimmung und Erkennung der Fossilien (1812), Mohs first introduced the ten-step hardness scale that is still in use today:
On the opposite end of the hardness scale is a rich deposit of calcium carbonate under development by the Sealaska Corp.
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. With our equipment, we drill quickly through rock of 5,000 to 6,000 psi.
PREDICT: The Mohs hardness scale ** ranks 10 minerals from softest to hardest.
Pitchure et al., Establishing a world-wide unified Rockwell hardness scale with metrological traceability, Metrologia 34, 331-342 (1997).
The VC layer is 0.0001" to 0.0008" thick and has a hardness of 3200 to 3800 on the Vickers hardness scale.
While the material exhibits high wear resistance (the hard phases of the material are > 1000HV50 on the Vickers hardness scale), its softer matrix means longer tool life when, say, bevel cutting the valve seats.
The Mohs hardness scale ranks rocks based on how easy or hard they are to scratch.
Glass microspheres (Mohs hardness scale = 5-6) enable low oil absorption, reducing the amount of polymer required.