This violet gas is the dominant species in hot sulfur vapors.

This violet gas is generated by heating sulfur above 720 °C, comprising 99% of the vapor at low pressure (1 mm Hg) at 530 °C.

[4] Gaseous disulfur has been detected emanating from the surface of Jupiter's moon Io, from the vicinity of Pele volcano.

[9] Singlet disulfur is believed to be the product of trisulfides with triphenylphosphine dibromide, or the thermal decomposition of dialkoxy disulfides.

However, the disulfur produced in that reaction is believed singlet because it undergoes formal hetero-Diels-Alder cycloadditions, not because of any spectroscopic evidence.