Inductively coupled plasmas were generated in pure SF6 and in Ar/SF6 and O-2/SF6 mixtures in a Gaseous Electronics Conference rf reference cell. Absolute total ion current densities, relative ion intensities, and ion energy distributions at the grounded electrode were measured and the influences of pressure, power, and mixture concentration on these quantities examined. In addition to ions derived directly or indirectly from SF6, ions resulting from quartz etching and sulfur oxidation contribute moderately to the total ion flux. The dominant sulfur-containing ion observed under most conditions is S+, indicating a large degree of SF6 dissociation.