Abstract: The crystal structure of the new mineral kamchatkite, a= 9.741(5), b= 12.858(6), c=7.001(3)Å, space group Pna2₁, Z = 4, has been determined through direct methods using 1430 intensities and refined to a final discrepancy index R = 0.055. It contains (SO₄) tetrahedra and Cu octahedra interconnected by oxygen atoms to form an electrostatically neutral three-dimensional arrangement of formula Cu₃O[SO₄]₂ which contains channels parallel to [001]. The channels are not empty but house KCl molecules.