Mohs Hardness Scale Hardness Mineral Test 1 2 Talc Gypsum Fingernail 3 Calcite Copper coin 4 5 Fluorite Apatite Knife blade or glass plate 6 7 8 9 K-feldspar Quartz Topaz Corundum Steel file 10 Diamond Specific Gravity : is the ratio of the weight of a given volume of a substance to the weight of an equal volume of water.
(7 8 9 K-feldspar Quartz Topaz Corundum Steel file 10; is; the ratio of the weight of a given volume of a substance to the weight of an equal volume of water)
7 8 9 K-feldspar Quartz Topaz Corundum Steel file 10
is
the ratio of the weight of a given volume of a substance to the weight of an equal volume of water