A synthetic gem material is one that is made in a laboratory, but which shares virtually all chemical, optical, and physical characteristics of its natural mineral counterpart.
- In 1837, Marc Antoine Gaudin made the first synthetic rubies by reacting alumina at a high temperature with a small amount of chromium as a colourant.
- In 1847, J. J. Ebelmen made white synthetic sapphires by reacting alumina in boric acid.
- In 1877, Frenic and Freil made crystal corundum from which small stones could be cut. Frimy and Auguste Verneuil manufactured artificial ruby by fusing BaF2 and Al2O3 with a little chromium at temperatures above 2,000 °C (3,630 °F).
- In 1903, Verneuil announced that he could produce synthetic rubies on a commercial scale using this flame fusion process.