锡石的晶体结构和形态的关系

本文对不同成因类型的锡石晶体形态进行了研究,并从PBC(周期性键链)理论出发,讨论了锡石晶体形态与晶体结构的关系。笔者认为,锡石晶体具有三种F面,即s{111}、e{101}、m{110},与Hartman对同样结构类型的金红石晶面性质划分有所差异。据锡石晶面结构性质所推导的理想晶体形态图,与晶体测量所得到的天然晶体形态图总体上相吻合。

The Relationship between Crystal Structure and External form of Cassiterite

An extensive observation has been made on the external form of cassiterites of various genetic types. The properties of their crystal faces are investigated by using PBC (periodic bond chain) theory and, as a result, three kinds of F faces are recognized, i. e., s{111}, m{110) and e{101}, in which s{111} has failed to be recognized by P. Hartman himself from rutile with the same crystal structural type. The forms of cassiterite have been drawn both through the measurement of natural crystals and through the deduction from its crystal structure, with the two results quite in agreement with each other.