SPECIFIC
GRAVITY
Specific gravity of a mineral is the weight of that mineral divided by the
weight of an equal volume of water (unitless property). Most rock-forming
minerals have specific gravities of 2.6 to 3.4. The ore minerals are
heavier (5 to 8).
Ice:
0.9
Quartz: 2.65
Most silicates: 2.5-3.0
Galena 7.5
Gold
19.3
Relative specific gravity: take two minerals
of about the same size, one in each hand, and you can tell which is the heavier
or has the higher specific gravity.