Erma Boécourt SA uses sapphire produced using the Verneuil and Kyropoulos processes.
The Verneuil process
The Verneuil process produces sapphire boules, also known as stalagmites. The technique uses flame fusion to melt pure aluminium oxide at a very high temperature (around 2000 C°). This creates drops that fall onto a seed crystal, which in turn becomes a sapphire boule (crystal).
Using this method, it can take from several hours to several days to grow a sapphire boule. A crystal is formed by superimposing layer upon layer of melted material.