The phase diagram of the system Ga‐S has been determined. Two maxima are found in the T‐X diagram, one at the composition of , the other at the composition of . The compound has a maximum melting point of 962° ± 4°C at a sulfur pressure of has a maximum melting point of about 1090°C at a sulfur pressure of 1.3 mm Hg. A range of liquid immiscibility exists between about 10 and 48 a/o (atom per cent) S and possibly also between about .