Fused quartz is a man made mineral, manufactured principly from sands. It is non-crystaline, and in a high purity state is a useful material for high performance fluid and gas delivery. It's mechanical and thermal properties are superior to that of glass
, priciply due to the purity (or, rather, the lack of impurities). For these reasons, it finds use in situations such as semiconductor fabrication and laboratory equiptment.
See also: quartz, list of minerals
Properties of Clear Fused Quartz
(Based on information in Fused Quartz Catalogue Q-7A, General Electric Company)