Vlodavetsite is a product of fumarole activity associated with the Great Tolbachik fissure eruption in Kamchatka in 1974 and 1976. This is always accompanied by fine-particle pyroclastic material. By using a RGNS X-ray goniometer and an automatic Syntex-P2₁ diffractometer, it is shown that vlodavetsite single crystals belong to the tetragonal system, the point group 4/m and the diffraction group I-/-(law of hkl maxima, h + k + 1 = 2n).