Clays and Clay Minerals, Volume 5 contains the proceedings of the Seventh National Conference on Clays and Clay Minerals held in Washington, D.C., on October 20-23, 1958. The papers explore developments in clays and clay mineralogy and cover topics such as differential settling tendencies of clay minerals in saline waters; effect of seawater on clay minerals; clay mineralogy of bottom sediments; relationships in the montmorillonite group of clay minerals; and water content of vermiculite. Advances in X-ray diftractometry of clay minerals are also discussed. This book is comprised of 23 chapters and begins with an analysis of differential settling velocities of individual clay mineral types and clay mineral mixtures in quiet saline water. The reader is then introduced to rapid dissolution of allophane and kaolinite-halloysite after dehydration; formation of chlorite-like structures from montmorillonite; regional clay mineral patterns in the Gulf of Mexico; and quantitative X-ray determinations of some aluminous clay minerals in rocks. The geology of clay deposits in parts of Washington and Idaho is also examined, along with the influence of exchangeable cations on the viscosity of clay suspensions. The final chapter presents the results of X-ray analysis of soil colloids by a modified salted paste method. This volume will be of value to earth scientists, mineralogists, and those interested in clays.