Age of Uraninites from Crystallographic Data

Abstract

THE criticism offered by Drs. Hoekstra and Katz is relevant in stressing certain chemical difficulties which may defy solution by conventional analyses—mineral chemists know such problems too well, for example, the role of iron in many minerals. They rely on chemical analyses of uraninites for their views; but I am suspicious of such analyses as they still report lead as PbO, when that of radiogenic origin should be PbO₂; that due to, say, galena, would be correctly given as PbO. Such duality exists in the position of oxygen, too, as it takes a double role crystallographically in many uraninites—such data cannot adequately be determined chemically.