Peter Tandy wrote: ------ I don't know too much about the radio side of quartz production, but it was needed during the war to make oscillators for the radio industry (and military, of course). These plates must be cut at a highly specific angle from a certain part of the crystal. ....... . -----------------------------------------------
I believe that natural quartz also had a number of other critically important uses at that time. Because of its very low coefficient of thermal expansion and high softening temperature, fused quartz (made from the natural form) was suitable for high-temperature "clean" containment tubes, ampules, crucibles, furnace rods, etc., as used in controlled-atmosphere (and vacuum) purification and preparation of technical materials. With good ultra-violet transmission, it also was used for UV light sources (e.g., high-pressure contained arcs,) and as windows for UV photo cells. (The use of fairly large, low surface to volume ratio, crystalline pieces as starting material would help in quickly producing a pure product.) Another industrial use, was in preparing low impurity ferro-silicon, which was added to "carry" silicon into various special-steel alloys, (e.g., very importantly, those used for electrical transformer-core laminations.) I don't know the relative quantities that went to these purposes, but along with its use in oscillators, it might help explain the buying up, and perhaps stockpiling, of what would have been seen as a vitally important industrial material. Bill Maddux
