Abstract
The composition range of tetrahedrite in the Cu-Sb-S system has been redetermined in detail at 300 degrees C, 355 degrees C, 400 degrees C, 500 degrees C, and 540 degrees C. The results at 500 degrees C and 540 degrees C are essentially similar to those of Skinner et al. (1972).Within the temperature range between 300 degrees C and 350 degrees C, the pseudotetrahderite solid solution has a narrow composition field along the Cu 2 S-Sb 2 S 3 join. Above 350 degrees C it merges with the tetrahedrite solid solution.Below 250 degrees C, tetrahedrite and pseudotetrahedrite solid solutions become unstable and both decompose finally to mixtures of famatinite, digenite, and elemental antimony.However, if the homogeneous tetrahedrite solid solution is quenched to room temperature from a temperature above 300 degrees C, it decomposes to form two solid phases. If these phases subsequently are heated to 95 degrees C, they react to form one homogeneous phase.
