Piypite is a rare potassium sulfate mineral with formula: K2Cu2O(SO4)2. It crystallizes in the tetragonal system and occurs as needlelike crystals and masses. Individual crystals are square in cross-section and often hollow. It is emerald green to black in color with a vitreous to greasy luster.
It was first described in 1982 for an occurrence in the Main Fracture of the Tolbachik volcano , Russia, Italy, and in a slag in the Rhineland-Palatinate Piypite occurs as a sublimate environment. Associated minerals include halite , langbeinite, tolbachite, aphthitalite , cotunnite, euchlorine, alarsite and lammerite in Kamchatka. On Vesuvius, it occurs with paratacamite