A heavy liquid is a dense liquid that sorts stones by specific gravity. A lighter stone floats in it, and a denser one sinks.
In more detail
In methylene iodide (SG 3.32), moissanite (SG 3.22) floats and diamond (SG 3.52) sinks. The liquid is toxic, so this is a laboratory method.
Related terms
- Specific gravity: Specific gravity compares a stone's weight with the weight of the same volume of water. It decides how much a stone of a given size weighs.
- Thermal diamond tester: A thermal diamond tester measures how fast a stone draws heat from a hot tip. Diamond conducts heat very well, so it reads “diamond”.