Raman spectra of mineral peretaite Ca(SbO) 4 (OH) 2 (SO 4 ) 2 ·2H 2 O were studied, and related to the structure of the mineral. Raman bands observed at 978 and 980cm −1 and a series of overlapping bands observed at 1060, 1092, 1115, 1142 and 1152cm −1 are assigned to the SO 4 2− ν 1 symmetric and ν 3 antisymmetric stretching modes. Raman bands at 589 and 595cm −1 are attributed to the SbO symmetric stretching vibrations. The low intensity Raman bands at 650 and 710cm −1 may be attributed to SbO antisymmetric stretching modes. Raman bands at 610cm −1 and at 417, 434 and 482cm −1 are assigned to the SO 4 2− ν 4 and ν 2 bending modes, respectively. Raman bands at 337 and 373cm −1 are assigned to O–Sb–O bending modes. Multiple Raman bands for both SO 4 2− and SbO stretching vibrations support the concept of the non-equivalence of these units in the peretaite structure.