### The Density of Common Rocks and Minerals

· The densities of rocks and minerals are normally expressed as specific gravity, which is the density of the rock relative to the density of water. This isn''t as complex as you may think because water''s density is 1 gram per cubic centimeter or 1 g/cm 3. Therefore, these numbers translate directly to g/cm 3, or tonnes per cubic meter (t/m 3).