.... The two blaubleibender covellites, low digenite, tetragonal phase, and protodjurleite were found to be metastable. The Cu (sub 1.9) S phase was demonstrated not to be a real phase in the system.The stable invariant points (Cu/S in parentheses) were as follows:Covellite (1.000 + or - 0.001) --> high...

...” yarrowite and spionkopite (Table 2 ), low digenite, tetragonal Cu 2 S, and a protodjurleite were found to be metastable. The temperatures of stable invariant points were in general agreement with literature values, as follows: covellite = high digenite + liquid sulfur (507 ± 2 °C) high chalcocite...