Sulfate chloride
The sulfate chlorides are double salts containing both sulfate and chloride anions. They are distinct from the chlorosulfates, which have a chlorine atom attached to the sulfur as the ClSO3− anion.
Many minerals in this family exist. Many are found associated with volcanoes and fumaroles. As minerals they are included in the Nickel-Strunz classification group 7.DG.
The book Hey's Chemical Index of Minerals groups these in subgroup 12.2.