PROCESS FOR FABRICATING A PRODUCT APPROPRIATE FOR PRODUCING PURE QUARTZ GLASS, PROCESS FOR PRODUCING PURE QUARTZ GLASS FROM SAID PRODUCT AND UTILIZATION OF SAID PRODUCT FOR GROWING PIEZOELECTRIC CRYSTALS

摘要

Process for fabricating a product appropriate for producing pure quartz glass from natural quartz which is not transparent (milky quartz) and process for treating said product for making a mold body from pure quartz glass. Furthermore, said product is appropriate as starting material for growing piezoelectric crystals in autoclaves.