Optical Fused Quartz and Its Contributions to Research

JSGT 1955 V39 T048-T057

It is the custom to call transparent, fused silicon dioxide "fused quartz" and milky or translucent fused silicon dioxide "fused silica." The production of fused silica and quartz had to await the development of a method of reaching temperatures of 1800°; moreover, the temperature had to be attainable rapidly while the heat content of the furnace had to be low, so as to provide for rapid cooling. It is curious that the manufacture of fused silica is very difficult – the methods are covered by numerous patents – while the making of fused quartz is simple and described in text-books written before the turn of the century. It is for this reason that The Thermal Syndicate, demonstrates to its visitors the manufacture of fused silica, but keeps the methods of making fused quartz a secret.

A. E. J. Vickers