Cuprodongchuanite (IMA2021-065), Pb4CuZn2(PO4)2(PO4)2(OH)2, is a new mineral from Sanguozhuang Village, Yunnan Province, China. It occurs as striking apple green crust-like radial or spherical aggregates of microscopic blade-like crystals on hemimorphite. Cuprodongchuanite is brittle with an irregular fracture, a Mohs hardness of 2½–3, and perfect cleavage on {011}. The calculated density is 6.10 g/cm3. The empirical chemical formula is (Pb4.06Ca0.02)Σ4.08(Cu1.07Cd0.01)Σ1.08Zn2.03[(P0.74As0.20S0.01Si0.01)Σ0.96O4]2(PO4)2(OH)2 based on 18 O atoms per formula unit. Cuprodongchuanite is triclinic, space group P$\bar 1$(#2), with unit-cell parameters. a = 4.7405(3) Å, b = 8.5023(5) Å, c = 10.2897(6) Å, α = 97.206(5)°, β = 101.877(5)°, γ = 91.786(5)°, V = 401.95(4) Å3 and Z = 1. Cuprodongchuanite’s name combines the prefix ‘cupro’ (for copper) with the root ‘dongchuanite’. As a member of the dongchuanite group, cuprodongchuanite features a dongchuanite-type structure with the general formula A4VIBIVB2(X1O4)2(X2O4)2(OH)2. In addition to providing a detailed characterisation of cuprodongchuanite, this study delves deeper into exploring the Jahn-Teller effect of Cu2+ ions at the VIB site, an important factor in the mineral’s crystallography. Employing the Δoct parameter, the study quantitatively links the degree of octahedral distortion to the Cu-Zn ratio. This method provides a refined understanding of the dongchuanite-type structure and offers an example for assessing similar mineral compositions where cations exhibit closely related properties.