a native variety of elemental sulphur containing a small proportion of selenium.
ΚΠ
1849 J. NicolMan. Mineral. 506Selen-sulphur.
1944 C. Palache et al. Dana's Syst. Mineral. (ed. 7) I. 142 Old specimens of reddish brown selensulfur from Vulcano gave n [sc. refractive index] 2·544–2.675 indicating 83–90·5 per cent Se; but this high Se content lacks confirmation.