Arnold, Powell, & Sandiford (2000; JMG, v.18, p.23-40) report a DQF
parameter of Iged-oa=24 kJ/mol to model the anthophyllite-gedrite with an
anth-feanth-ged IMOS model, but do not present any details about what data
was used to derive the parameter.  Furthermore, it was used with the
updated1996 dataset, not the 1998 dataset.

This model is fairly straightforward to code as it is ideal with only the
DQF parameter to add for non-ideality.  I have coded this model for
THERMOCALC, but have not used it because I was unclear on the details of
its derivation.  It seems to me that if there is an anthophyllite-gedrite
parameter (presumably representing the tschermaks subst), isn't it likely
there would also be a corresponding Fe-tschermak in the
ferroanthophyllite-gedrite binary?


Doug Tinkham
Dept. of Geology, University of Alabama
202 Bevill Building, Box 870338
Tuscaloosa, AL 35487-0338
205-348-9293 (Dept. office)
205-348-0818 (Fax)
e-mail:  [log in to unmask]