22. Verneuil
Also known as the “flame fusion” process that was developed in the late 1800s, verneuil was the first successful commercial manufacturing of synthetic gemstones. Created by French chemist Auguste Verneuil, the process is predominantly used to produce sapphire varieties of corundum, rubies, diamond simulants rutile and strontium titanate. The ingredients used in the verneuil process are in powder form and burned over a oxyhydrogen flame, after which the melted droplets are then crystallised into a boule or crystal ingot. Many consider the verneuil process as the first step towards the growth of modern industrial crystal technology.
