Substance Hardness Talc 1 Amber , Fingernail, Ivory , Shell, Jet 2.5 Gold 2-3 Bronze , Coral , Pearl 3 Azurite 3.5-4 Iron 4 Glass 5 Lapis lazuli 5-5.5 Turquoise 5-6 Opal 5.5-6.5 Moonstone 6-6.5 Peridot 6.5 Jade 6.5-7 Amethyst , Chalcedony , Quartz , Steel (pocket knife) 7 Garnet 6.5-7.5 Tourmaline 7-7.5 Zircon 7.5 Aquamarine , Emerald 7-8 Spinel , Topaz 8 Chrysoberyl 8.5 Ruby , Sapphire 9 Diamond 10 MOHS SCALE The Mohs Scale of Hardness measures a substance's hardness, that is, how resistant it is to being scratched.
(The Mohs Scale of Hardness; measures; a substance's hardness) (it; is; )
The Mohs Scale of Hardness it
measures is
a substance's hardness