Abstract: Priderite is the name suggested for a new mineral with the formula (K,Ba)_1·3(Ti,Fe)₈O₁₆. X-ray diffraction studies show that the mineral is body-centred tetragonal with a 10·11, c 2·96 Å. Structurally the mineral resembles cryptomelane, KMn₈O₁₆, the Ti of priderite being equivalent to the Mn of cryptomelane. Synthetic K- and Ba-priderites appear to be isostructural and they are probably members of a series analogous to cryptomelane-hollandite.