Nomenclature of Silica

Abstract

FOR many years the term ‘fused quartz’ has been used for describing vitreous silica prepared by the fusion of crushed quartz crystals. In some quarters the term ‘vitreous silica’ has been reserved for material made from an acid-washed sand, usually containing larger amounts of impurities. Unfortunately, the term ‘fused quartz’ is often abbreviated to ‘quartz’ in the later pages of a publication, and sometimes even in the title. A quick glance at Chemical Abstracts subject index for 1956 revealed four abstracts dealing with “quartz”, where it was obvious that vitreous silica was meant¹. The electrophoresis of “quartz particles in a quartz cell” is mentioned in one abstract. It is highly unlikely that the electrophoresis cell was of crystalline quartz ; it was presumably vitreous silica. The question remains, were the particles also of vitreous silica ? A recent example of the misnaming of silica is a paper dealing with vitreous silica and probably cristobalite² and headed “Whisker growth from quartz”. It contains the sentence “The quartz substrate … had a skin of devitrified quartz … ”.