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Bornite, chalcopyrite, idaite, covellite, yarrowite, spionkopite, anilite, digenite, djurleite, and chalcocite have been identified in quartz veins from the Vielsalm area. Stavelot Massif, Belgium. The identification of these copper sulfides is confirmed by electron-microprobe analyses. The association of primary sulfides indicates that the bornite-bearing quartz veins crystallized above 300-350 degrees C, whereas the chalcocite-bearing quartz veins crystallized below 200 degrees C. Relations among sulfides indicate the occurrence of two sequences of transformation, responsible of the formation of secondary sulfides: chalcocite-H double right arrow chalcocite-M double right arrow djurleite double right arrow low digenite or (anilite + djurleite) double right arrow yarrowite + spionkopite double right arrow covellite + oxidation minerals, and bornite double right arrow idaite + chalcopyrite double right arrow covellite + oxidation minerals. The crystallization of chalcocite-M, djurleite, and low digenite or (anilite + djurleite) took place between 103.5 and 72 degrees C. The associations idaite + chalcopyrite, yarrowite + spionkopite, and covellite + oxidation minerals, were produced under meteoric conditions. The source of Cu and of the other elements present in the quartz veins must be sought in the host chloritoid-bearing schists.