Ajoite (K,Na)Cu 7 AlSi 9 O 24 (OH) 6 ·3H 2 O is a mineral named after the Ajo district of Arizona. Raman and infrared spectroscopy were used to characterise the molecular structure of ajoite. The structure of the mineral shows disorder which is reflected in the difficulty of obtaining quality Raman spectra. The Raman spectrum is characterised by a broad spectral profile with a band at 1048cm −1 assigned to the ν 1 (A 1g ) symmetric stretching vibration. Strong bands at 962, 1015 and 1139cm −1 are assigned to the ν 3 SiO 4 antisymmetric stretching vibrations. Multiple ν 4 SiO 4 vibrational modes indicate strong distortion of the SiO 4 tetrahedra. Multiple AlO and CuO stretching bands are observed. Raman spectroscopy and confirmed by infrared spectroscopy clearly shows that hydroxyl units are involved in the ajoite structure. Based upon the infrared spectra, water is involved in the ajoite structure, probably as zeolitic water.