Created by Aram Dulyan (User:Aramgutang)

This diagram illustrates the Verneuil process (flame fusion) used to synthesise rubies and other forms of corundum. Finely powdered aluminium oxide is released from the container at the top, and travels down with the oxygen. At the point where the oxygen enters the hydrogen environment, combustion occurs with a flame of at least 2000°C. The aluminum oxide powder melts into small droplets, which fall onto the support below, recrystallising into a boule. The support is continuously and slowly withdrawn, allowing a large boule to form. Diagram created using Inkscape.