Polymorphism and Polytypism.

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Abstract:

Polymorphic transitions of binary sulfides were examined for possible differences in composition between polymorphs by direct synthesis or by the highly sensitive method of testing the transition temperature for dependence on sulfur fugacity. Experimental study of the Hg-S, Fe-S, and Ag-S systems, plus compilition of published data on 33 other binaries revealed a total of 16 transitions where temperatures and compositions or fugacity-dependence are sufficiently well known to determine any change in composition between polymorphs because only one of these transitions is isocompositional, it is clear that sulfide transitions, in general, are between phases of different compositions. Consequently, definitions of polymorphs and of transitions or transformations need revision. Modified author abstract

Author(s):
Barnes, Hubert L.
Author Organization(s):
PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF GEOSCIENCES
Descriptive Note:
Final rept. 1 Feb 69-31 Dec 72,
Pagination:
0042

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release

RECORD

Collection: TR
Identifying Numbers
Report Number(s):
AROD-8011:1-C
Contract/Grant Number(s):
DAHC04-69-C-0043
Project Number(s):
AROD-P-8011-C
Monitor Series:
8011:1-C
 Subject Terms
Communities of Interest:
No COI(s) Identified
Descriptor(s):
*SULFIDES, *PHASE STUDIES, PHASE DIAGRAMS, CRYSTAL STRUCTURE, PYRITE, REACTION KINETICS, TEMPERATURE, SULFUR, CHEMICAL EQUILIBRIUM
Field(s)/Group(s):
Physical Chemistry, Geology, Geochemistry and Mineralogy
Keyword(s):
MARCASITE, CHEMICAL COMPOSITION, CINNABAR, *POLYMORPHISM, FUGACITY
Report Date:
1973 Jan 31