Skip to main content
U.S. flag

An official website of the United States government

The Fe-Sb-S system

January 6, 2022

The phase relations in the Fe-Sb-S system from 300° to 800° C have been determined using new experimental data on phase assemblages and univariant equilibria in conjunction with information from the literature. Estimates have been made for the standard free energies of formation as a function of temperature for stibnite, berthierite, gudmundite, and FeSb2 . Comparison of calculated mineral stabilities with published information on mineral assemblages suggests that apparently contradictory mineral associations may well represent equilibration at different (but all low) temperatures with subsequent lack of reaction as temperature fell to the temperature of observation. Resolution of the complicated, low-temperature phase relations will require additional thermochemical data of unusually high accuracy that might well be supplemented by careful study of natural materials.

Berthierite, gudmundite, and aurostibite are clearly stable only under conditions of relatively low sulfur activity. FeSb2 requires such low sulfur activity for its stable existence that it is seldom, if ever, to be expected as a mineral. The tendency for the common ore mineral galena to react with berthierite to yield pyrrhotite plus a lead sulfantimonide operates to make berthierite a rather uncommon mineral.

Citation Information

Publication Year 1971
Title The Fe-Sb-S system
DOI 10.2113/gsecongeo.66.1.121
Authors Paul B. Barton
Publication Type Article
Publication Subtype Journal Article
Series Title Economic Geology
Index ID 70227281
Record Source USGS Publications Warehouse