id="p-1">Martyite, Zn3(V2O7)(OH)2·2H2O, a new mineral species from the Blue Cap mine, near La Sal, San Juan County, Utah, U.S.A., is named for its discoverer, Joe Marty, of Salt Lake City, Utah, who is also responsible for the discovery of three other new minerals from the same area. Martyite formed from post-mining leaching and oxidation of V–U oxide replacements of organic matter. It occurs as thin yellow-orange to red-orange plates and flakes with a rounded or irregular outline, up to 0.01 mm thick and 1 mm long, typically in irregularly intergrown mats and rosette-like clusters. The mineral has a pale yellow-orange streak, an adamantine luster, a Mohs hardness of about 3, and two cleavages, {001} perfect and {110} good. The measured density is 3.37(3) g/cm3, and the calculated density is 3.375 g/cm3. It is optically uniaxial (+), ω 1.797(3), ε 1.806(3), and distinctly pleochroic: O >> E. Electron-microprobe analyses provided: ZnO 46.93, CoO 2.39, CaO 0.58, MgO 0.03, V2O5 39.47, H2O 12.06 (calc.), total 101.46% which, based on V = 2