Notes on British Sources of Sands for Making Colourless Glass

JSGT 1940 V24 T197-T239

 For the complete study of a sand it is desirable to have knowledge of chemical composition, grain sizes, geological origin and characteristics and mineralogical composition. The account given here makes no pretensions to such completeness. Geological maps were not infrequently consulted in seeking clues to any deposits or areas likely to contain deposits not previously studied, and in a few instances the mineral characteristics of the sands were noted, although not necessarily recorded in what follows. The subject is dealt with from the point of view of the chief criteria of sands suitable for making colourless glass-namely, a sufficiently low total iron oxide content, ascertained by chemical analysis, and grain sizes suitably distributed and limited so that excessive coarseness and fineness are avoided, both criteria being defined by the Society of Glass Technology's Specification for Sands for Colourless Glassmaking. The need for high silica content is less important than that of low iron oxide content, and the analysis for silica was not always performed. If the sand from a deposit, reasonably well sampled, was found after water washing or other practicable treatment to have too high an iron oxide content for colourless glass, it was regarded as time wasted to proceed to ascertain the silica, alumina or other constituent.

Professor W. E. S. Turner