X-ray radiometric study of dehydration products of goethite and lepidocrocite

Abstract

Two polymorphic modifications of iron oxide hydrate are known in nature - goethite a-FeO(OH) or HFeO₂ and lepidocrocite y-FeO(OH). However, until now in the literature and practice for loose ferruginous formations the name hydrogetite is common, which, according to E. J. Rohde and B. K. Brunovsky, represents a hydrate of iron oxide. K. Brunovsky, is a solid solution of zeolite-type water in goethite. The presence of such water should cause an increase in the interplanar distances and, consequently, in the unit cell parameters of the so-called hydrogetite (the same applies to hydrohematite). But, as X-ray radiometric studies show, the changes in the values of interplanar distances are so insignificant that they are within the error of experience. Such friable formations, apparently, are finely dispersed goethite containing a considerable amount of adsorbed water. Debaeograms of hydrogetite differ from ordinary goethite only by strong blurriness and width of diffraction lines.