Solid Inclusions in Man-made Quartz Crystals Electron Microscopic Investigation

Short‐term hydrothermal experiments were carried out for a more detailed study of solid inclusions in man‐made quartz crystals. In these experiments the crystals which usually are included in quartz occur on the surface of the seed and are only partly overgrown by quartz. Optical observations and SEM and EDS investigations have shown that: 1. The formation of inclusions is a special event in the history of autoclave growth of quartz, the process being controlled by the formation of many sites of increased surface tension. 2. Epitaxial phenomena are of great importance in the formation of inclusions. 3. The solid inclusions are of quartz (30%) and of the Na‐Fe‐silicate Phase 1 (70%). Both occur as single crystals larger than 3 μm as well as clusters of crystals smaller than 2 μm. 4. The several other phases observed as inclusions are of no importance for the quality of the man‐made quartz crystals. Russian text ignore.