DISILICATES AND RING SILICATES

A second edition, in two parts, of Volume 1 of this well-known reference series. This volume deals mainly with the disilcates and ring silicates including the epidote,melilite, cordierite, and tourmaline groups. In addition to the minerals dealt with in the first edition, some of the rarer but typical minerals in the calc-silicate rocks andthe accessory minerals of nepheline-syenites and related rocks have been included. The orthosilicates, in particular the olivine, garnet and humite groups are coveredin Volume 1A. In the years since the first edition was published, the quantity and scope of research on the disilicates and ring has grown enormously and has given rise to a widevariety of literature. This book, which has been completely rewritten and considerably expanded, summarizes the important research results and presents them in anorganized fashion. Each mineral chapter is divided into sections on structure, chemistry, optical and physical properties, distinguishing features and paragenesis. Each chapter is headedby a tabulation of mineral data and a sketch showing optical orientation, and concludes with full references to the literature. Diagrams of the crystal structures arepresented and are followed by a discussion of the structural features. The chemical sections include a large number of analyses from which structural formulae havebeen calculated, illustrating the chemical and paragenetical variation exhibited by each mineral; phase equilibria in relevant systems are fully considered. In thesections on optical and physical properties, particular attention is paid to the correlation of these properties with chemical composition. The principal modes of occurrence aredescribed and discussed in the paragenesis sections; here again correlation with chemistry is emphasized.