US EPA

6868956 

Journal Article 

A MICROPROBE STUDY OF ANTIGORITE AND SOME SERPENTINE PSEUDOMORPHS 

Dungan, MA; , 

1979 

Yes 

Canadian Mineralogist
ISSN: 0008-4476
EISSN: 1499-1276 

MINERALOGICAL ASSOC CANADA 

QUEBEC 

17 

771-784 

WOS:000208514700011 

Microprobe analyses of serpentine pseudomorphs after olivine, orthopyroxene and clinopyroxene demonstrate partial inheritance of compositional characteristics from the parent phases. Bastites have higher chromium and aluminum contents than mesh-textured serpentine. Qualitative estimates of elemental mobility during serpentinization are Fe >> Al > Cr. The observed persistence of lizardite bastites in progressively metamorphosed serpentinites suggests a compositional control. The presence of aluminum in solid solution may increase the thermal stability of lizardite with respect to antigorite or to partly dehydrated assemblages. The microprobe analyses confirm the compositional differences between pseudomorphic serpentines (lizardite and chrysotile) and antigorite that are predicted by their slightly different structural formulae: antigorites have lower H2O, lower octahedral occupancies and relatively high SiO2.