A comparison of the structures and geometric stabilities of stilpnomelane and parsettensite

Abstract

Structural models for the islandlike modulated phyllosilicates, stilpnomelane and parsettensite, were examined by distance least-squares (DLS) calculations. Parsettensite occurs naturally only near the Mn end-member, whereas stilpnomelane may be both Mn and Fe2+ rich. Models for compositions between Fe2+ and Mn2+ end-member stilpnomelane demonstrated that the stilpnomelane structure is geometrically stable across the composition range. In principle, therefore, stilpnomelane may occur at Mn end-member compositions. -from Authors Show more