Specific gravity

From Conservapedia

Specific gravity is a property of any given sample of matter, defined as the ratio of its density to that of water at a given temperature.

Substances are denser than water if they have a specific gravity greater than 1, and less dense if it is less than 1. However, it does not follow that water has a specific gravity of 1, since the density of water varies according to the temperature.

The use of specific gravity is generally discouraged in present-day scientific and technical writing, with absolute values of density preferred.