Other Classifications of Silicates

Abstract

Machatschki (1928) seems to have been the first to realize that the kind and the degree of linkage of [SiO₄ tetrahedra is a suitable property for the classification of silicates. Since at that time only a few silicate structures had been determined, this was an extremely far-sighted suggestion. Two years later Bragg (1930) and Náray-Szabó (1930), having access to the structures of the most important rock-forming silicate minerals, followed Machatschki’s suggestion and created what is now usually referred to as “Bragg’s classification of silicates” (Table 8.1). This classification was based on the [SiOJ tetrahedra and the dimensionality of their linkage, and took account of the partial replacement of silicon by tetrahedrally coordinated aluminum. Berman (1937) extended this partial replacement of silicon to beryllium, and Strunz (1938) extended it further to include phosphorus, arsenic, germanium, titanium, and iron.