The hardness of a material is measured against the scale by finding the hardest material that that the given material can scratch, or the softest material that can scratch the given material. Mohs original scale is as follows: Hardness Material Absolute Hardness 1 Talc (Mg3Si4O10(OH)2) 1 2 Gypsum (CaSO4·2H2O) 3 3 Calcite (CaCO3) 9 4 Fluorite (CaF2) 21 5 Apatite (Ca5(PO4)3(OH-,Cl-,F-)) 48 6 Orthoclase (KAlSi3O8) 72 7 Quartz (SiO2) 100 8 Topaz (Al2SiO4(OH-,F-)2) 200 9 Corundum (Al2O3) 400 10 Diamond (C) 1500 To give some examples from everyday life, a fingernail has a hardness of 2; a copper penny, about 3; a knife blade, 5; window glass, 5.5; and a steel file, 6.5. Here are the Mohs scale ratings for various gemstones: Gem Hardness Info Page Diamond 10.0 Diamond Information Page Ruby 9.0 Ruby Information Page Sapphire 9.0 Sapphire Information Page Star Sapphire 9.0 Star Sapphire Information Page Chrysoberyl 8.5 Chrysoberyl Information Page Spinel 8.0 Spinel Information Page Topaz 8.0 Topaz Information Page Azotic Topaz 8.0 Azotic Topaz Information Page Mystic Topaz 8.0 Mystic Topaz Information Page Emerald 7.5 - 8.0 Emerald Information Page Aquamarine 7.5 - 8.0 Aquamarine Information Page Beryl 7.5 - 8.0 Beryl Information Page Andalusite 7.5 Andalusite Information Page Garnet 7.0 - 7.5 Garnet Information Page Iolite 7.0 - 7.5 Iolite Information Page Quartz 7.0 Quartz Information Page Mystic Quartz 7.0 Mystic Quartz Information Page Almandine Garnet 6.5 - 7.5 Almandine Garnet Information Page Amazonite 6.0 - 6.5 Amazonite Information Page Amethyst 7.0 Amethyst Information Page Ametrine 7.0 Ametrine Information Page Chalcedony 6.5 - 7.0 Chalcedony Information Page Hiddenite 6.5 - 7.0 Hiddenite Information Page Jadeite 6.5 - 7.0 Jadite Information Page Nephrite 6.5 - 6.5 Nephrite Information Page Jasper 6.5 - 7.0 Jasper Information Page Kunzite 6.5 - 7.0 Kunzite Information Page Kyanite 6.0 - 7.0 Kyanite Information Page Moonstone 6.0 - 6.5 Moonstone Information Page Orthoclase 6.0 - 6.5 Orthoclase Information Page Peridot 6.5 - 7.0 Peridot Information Page Pyrope Garnet 6.5 - 7.5 Pyrope Garnet Information Page Rhodolite Garnet 6.5 - 7.5 Rhodolite Garnet Information Page Ruby Zoisite 6.5 - 7.0 Ruby Zoisite Information Page Spessartite Garnet 6.5 - 7.5 Spessartite Garnet Information Page Spodumene 6.5 - 7.0 Spodumene Information Page Tanzanite 6.5 - 7.0 Tanzanite Information Page Tourmaline 7.0 - 7.5 Tourmaline Information Page Zircon 6.5 - 7.5 Zircon Information Page Opal 5.5 - 6.5 Opal Information Page Moss Opal 5.5 - 6.5 Moss Opal Information Page Fire Opal 5.5 - 6.5 Fire Opal Information Page Lapis Lazuli 5.0 - 6.0 Lapis Lazuli Information Page Turquoise 5.0 - 6.0 Turquoise Information Page Diopside 5.0 - 6.0 Diopside Information Page Sphene 5.0 - 5.5 Sphene Information Page Cat's Eye Apatite 5.0 Cat's Eye Apatite Information Page Apatite 5.0 Apatite Information Page Fluorite 4.0 Fluorite Information Page First Published: September-16-2006 © 2003-2008 GemSelect.com all rights reserved. Reproduction (text or graphics) without the express written consent of GemSelect.com (SETT Company Ltd.) is strictly prohibited. |
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| Last Updated ( Thursday, 22 October 2009 16:01 ) | ||||||||||
