====== Mohs scale of hardness ======
**Mohs**, **Mohs hardness scale**

The so-called Mohs scale assigns the numbers from 1 to 10 to the material hardness 1 for the softest, 10 for the hardest. It is named after the German geologist and mineralogist Friedrich Mohs (1773-1839). Mohs scratched different minerals against each other and so aligned them according to their hardness. Mohs (MOH) therefore holds as a measuring unit for the material hardness.

===== Comparison Chart =====

^Material ^Mohs hardness ^
|Talc, talcum |1|
|Plaster |2|
|[[Silver]] |2.5|
|[[Gold]], [[aluminium]], copper |2.5 - 3|
|Calcite, marble |3|
|[[Acrylic glass|Plexi-/Acrylic glass]], coral |3 - 4|
|Fluorspar, iron |4|
|[[Mineral glass|Mineral watch-glass]], apatite |5|
|[[Steel]], porcelain, lapis lazuli, turquoise |5-6|
|Feldspar, hardened steel |6|
|Hematite, opal |5.5 - 6.5|
|Moonstone |6 - 6.5|
|Agate, Jasper |6.5 - 7|
|[[Quartz]], rock crystal, amethyst, citrine, [[onyx]] and [[zirconium|zircon]] |7|
|Turmaline |7 - 7.5|
|Almandine |7.5|
|Carbide |7 - 8|
|Aquamarine, beryl, emerald, |7.5 - 8|
|Topaz, Hardlex watch glass |8|
|[[Ruby]], [[sapphire]] ([[corundum]]) |9|
|[[Diamond]] |10|


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