Solid solutions along bornite-digenite, bornite-chalcocite, and bornite-chalcopyrite joins were cooled at various rates, some in experiments lasting as long as 7 months. The stability of exsolution lamellae is controlled by several factors in addition to rate of cooling, so these lamellae need not indicate rapid cooling. Neither this nor any of the other textures formed was diagnostic of any particular temperature or cooling rate, but the experiments suggest a number of rules on the relative stability of the various exsolution textures. The experiments support earlier work in showing that veining, mutual boundary, textures, and textures suggestiong replacement may all result from exsolution. They also point to dangers in the acquisition of thermometric data by rehomogenization.