I. INTRODUCTIONThe pegmatites discussed in this paper occur entirely in the granite region of Suchou (Wuhsien), Kiangsu and most of them are found within the marginal zone of the said igneous body. Although much work has been done on the Suchou granite by former geologists [19; 13; 21; 12], there is no literature dealing particularly with the pegmatites which are in intimate