The new mineral zincoberaunite, ideally ZnFe³⁺ ₅(PO₄)₄(OH)₅·6H₂O, the Zn analogue of beraunite, is found in the Hagendorf South granitic pegmatite, Hagendorf, Bavaria, Germany, in two associations: (1) with potassium feldspar, quartz, jungite, phosphophyllite and mitridatite (the holotype) and (2) with flurlite, plimerite, Zn-bearing beraunite, schoonerite, parascholzite/scholzite, robertsite and altered phosphophyllite (the cotype). Zincoberaunite occurs as radial or randomly oriented aggregates of flexible fibers up to 1.5 mm long and up to 3 μm thick. D_calc is 2.92 g/cm³ for the holotype and 2.94 g/cm³ for the cotype. Zincoberaunite is optically biaxial (–), α = 1.745(5), β = 1.760(5), γ = 1.770(5), 2V_meas = 80(5)°. Chemical composition of the holotype (electron probe microanalyser; H₂O by gas chromatography of ignition products) is: MgO 0.28 wt%, CaO 0.47 wt%, ZnO 7.36 wt%, Al₂O₃ 0.88 wt%, Fe₂O₃ 42.42 wt%, P₂O₅ 31.63 wt%, H₂O 16.2 wt%, total 101.1 wt%. The empirical formula calculated on the basis of 27 oxygen atoms per formula unit is (Zn_0.83Ca_0.08Mg_0.06)_∑0.97(Fe³⁺ _4.88Al_0.16)_∑5.04(PO₄)_4.09(OH)_4.78 · 5.86H₂O. Zincoberaunite is monoclinic, space group C2/c; refined unit cell parameters (for the holotype at room temperature and the cotype at 100 K, respectively) are: a 20.837(2) and 20.836(4), b 5.1624(4) and 5.148(1), c 19.250(1) and 19.228(4) Å, β 93.252(5) and 93.21(3)°, V 2067.3(3) and 2059.2(7) ų, Z = 4. The crystal structure of the holotype specimen has been refined by the Rietveld method (R_p = 0.30 %; R_B = 0.18 %) whereas the structure of the cotype has been solved from the single crystal data and refined to R₁ = 0.056 based on 1900 unique reflections with I > 2σ(I). The strongest reflections of the powder X-ray diffraction pattern of the holotype specimen [(d, Å) (I, %) (hkl)] are: 10.37 (100) (200), 9.58 (32) (002), 7.24 (26) (20–2), 4.817 (22) (111), 4.409 (13) (112), 3.483 (14) (11–4, 600), 3.431 (14) (404), 3.194 (15) (006, 31–4), 3.079 (33) (314).