hardness scale


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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.

Mohs scale

A system that qualifies minerals according to hardness, ranging from talc (1) to diamond (15).

Mohs,

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
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.
This first hardness scale was still very unreliable because the testing implements themselves (file, knife and fingernail) were not standardized and could vary in hardness.
Teachers: Students can refer to the Mohs hardness scale in the activity on T3, in the Teacher's Edition.
Since 1997, NIST and other national metrology institutes have been working on the establishment of worldwide-unified Rockwell hardness scales (1).
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.
Versaflex CL2003 is rated 30 Shore 00 because the gel-like polymer is not measurable on the familiar Shore A hardness scale.
A rock with a rank of 9 on the Mohs hardness scale is --.
U-600 vulcanizates, for instance, are available in a relatively high hardness range, whereas all other grades give a vulcanizate hardness in the low to medium durometer A hardness scale.
The net effect is to extend the useful range of PUR elastomers downward on the hardness scale from currently attainable levels, BASF claims.
Testing on the P&J hardness scale resulted in similar results, with the proprietary compound demonstrating superior thermal stability.
The DigiChamber operates according to the ASTM D2240 and DIN 53505 standards and can be equipped to test for a range of durometer hardness scales.