.... Sheet serpentine generally, and lizardite and amesite specifically, can adopt alternative crystallographic stacking arrangements called polytypes. Polytypism has been extensively studied in fully ordered crystals, but it remains largely enigmatic in the more common semi-disordered crystals that in long...

...Hong Zheng; Sturges W. Bailey Abstract The crystal structure of amesite-2H 1 from the Postmasburg Mn ores of South Africa has been refined to R = 4.7% using Siemens P4 rotating-anode MoKalpha X-ray data and SHELXL-93 software. Partial ordering of tetrahedral Si,Al and especially of octahedral Mg,Al...

...Andrzej Wiewiora; Jose A. Rausell-Colom; Maria Teresa Garcia-Gonzalez Abstract The crystal structure of a violet phyllosilicate from the serpentinite massif of the Sobotka Mountains, lower Silesia, Poland, identified as amesite by powder diffractometry, wet chemical analysis, and IR absorption...

...Cynthia S. Anderson; S. W. Bailey Abstract The crystal structure of amesite-2 H 2 from the Saranovskoye chromite deposit, North Urals Mountains, USSR, was refined in space group C 1 to a residual of 5.7% with 1719 independent reflections. The study was undertaken to resolve conflicting...

...S. H. Hall; S. W. Bailey Abstract Amesite crystals from the Dufek Massif, Pensacola Mountains, in Antarctica have been identified as the 2 H 2 and 6 R polytypes. The crystals universally are twinned on (001), and the twinned aggregates exhibit apparent hexagonal diffraction symmetry. An untwinned...

...John W. Gruner Abstract An investigation of amesite with x-rays discloses that the mineral cannot be a simple chlorite. It has essentially a kaolinite structure, with which a few chlorite units are interstratified. As chlorites increase in Al at the expense of Si, there is a shrinkage normal...

...Carlos J. Serna; Bruce D. Velde; Joe L. White Abstract In recent years a considerable effort has been directed to the understanding of the cation distribution in amesites, i.e ., 1:1 layer silicates with the maximum amount of tetrahedral and octahedral Al-substitution. Thus, amesite can...

...C. J. Serna; B. Velde; J. L. White Abstract An IR investigation of natural and synthetic amesites has been made. The natural amesite from Chester, Massachusetts, and certain synthetic samples show order in the Al for Si substitution in tetrahedral sheets. Their IR spectra are characterized by sharp...

...Teddy Parra; Olivier Vidal; Thomas Theye Abstract Iron chlorite with compositions intermediate between the two end-members daphnite [Fe 5 Al 2 Si 3 O 10 (OH) 8 ] and Fe-amesite [Fe 4 Al 4 Si 2 O 10 (OH) 8 ] were synthesized from gels, under f O 2 conditions defined by the solid oxygen buffer Fe-FeO...