Wikipedia
Fused quartz or fused silica is glass consisting of silica in amorphous (non- crystalline) form. It differs from traditional glasses in containing no other ingredients, which are typically added to glass to lower the melt temperature. Fused silica, therefore, has high working and melting temperatures. The optical and thermal properties of fused quartz are superior to those of other types of glass due to its purity. For these reasons, it finds use in situations such as semiconductor fabrication and laboratory equipment. It has better ultraviolet transmission than most other glasses, and so is used to make lenses and other optics for the ultraviolet spectrum. Its low coefficient of thermal expansion also makes it a useful material for precision mirror substrates.
Usage examples of "fused quartz".
In the middle will be a series of fused quartz windows, opening into a large room just under the outer shell.
Enormous retorts of fused quartz must be made, and the Dome is stiflingly hot now, for the sun is beating down on it and enormous oxy-hydrogen flames are needed to fuse the refractory quartz.
Proudly he gestured at a row of big objects which looked like heavy nozzles of fused quartz mounted on swivels above square, copper-shielded mechanisms.
Between the poles of the galvanometer was stretched a slender thread of fused quartz plated with silver, only one one- thousandth of a millimetre in diameter, so tenuous that it could not be seen except in a bright light.
Through the fused quartz of the window she was even able to make out Dale's features.
The other four were gazing through the thick fused quartz panes across the unlovely Plain as though it were the most beautiful view on Earth.
Here, within a metre-wide sphere of perfect orbit-fused quartz, the quartz covered with a mirror coating of niobium, were eight thumb-sized ceramic cells, each containing approximately a thousand atoms of copper.
Chester fingered the case, opened it and took out the slender two-inch tube of fused quartz with its cluster of components in a quarter-inch bulb at one end.