Crystallochemical Characteristics of Mineral Classes and Groups

Abstract

Here I give a very brief crystallochemical characterization of each mineral class, together with the principal subclasses, by reference to the most important groups of minerals. Of course, many interesting details have to be omitted for lack of space, as do numerous relations between species and groups. The importance of a class is to be judged not merely by the number of species it contains but also by the number and variety of structure types. Classes less studied from the viewpoint of the present principle are given more attention than ones fully dealt with in the literature, such as the silicates, whose crystal chemistry is well known. The same consideration has been applied to the use of figures for the structure types. Preference has been given to recently elucidated structures, especially ones with chain and layer patterns. The classes are considered in the following sequence: 1) homoatomic compounds; 2) sulfides and analogs; 3) oxygen compounds; 4) halides. This is the sequence used in Part 2, and each section of this chapter is a brief introduction to the crystal chemistry of the class.