# If a mineral has a specific gravity of 7.0. What does this mean?

It means that the mineral is 7.0 times more dense than water at ${4}^{\circ} C$.
The specific gravity (also called relative density) of a material is a ratio of the density of that material to the density of water at ${4}^{\circ} C$, which is the temperature at which water has its maximum density.
Density itself is defined as mass per unit volume : $\rho = \frac{m}{V}$.
thereforeSG=rho_(rel)=(rho_s)/(rho_(water at 4^@C).