A type of blowpipe (chalumeau) invented by the French chemist Auguste Victor Louis Verneuil (1856-1913), with which he first made synthetic rubies. His results were published in 1904. The apparatus is used today (sometimes in banks of several hundred units) to make synthetic varieties of corundum and other synthetic gemstones; but other processes have been developed that are used less frequently, e.g. hydrothermal, flux fusion, and Czochralski processes. The verneuil process is sometimes referred to as 'flame fusion'.
From: An Illustrated Dictionary of Jewelry, autor: Harold Newman, publishers: Thames and Hudson