A new mineral, droninoite, was found in a fragment of a weathered Dronino iron meteorite (which fell near the village of Dronino, Kasimov district, Ryazan oblast, Russia) as dark green to brown fine-grained (the size of single grains is not larger than 1 μm) segregations up to 0.15 × 1 × 1 mm in size associated with taenite, violarite, troilite, chromite, goethite, lepidocrocite, nickelbischofite, and amorphous Fe³⁺ hydroxides. The mineral was named after its type locality. Aggregates of droninoite are earthy and soft; the Mohs hardness is 1–1.5. The calculated density is 2.857 g/cm³. Under a microscope, droninoite is dark gray-green and nonpleochroic. The mean (cooperative for fine-grained aggregate) refractive index is 1.72(1). The IR spectrum indicates the absence of S O₄²⁻ and C O₃²⁻ anions. Chemical composition (electron microprobe, partition of total iron into Fe²⁺ and Fe³⁺ made on the basis of the ratio (Ni + Fe²⁺): Fe³⁺ = 3: 1; water is calculated from the difference) is as follows, wt %: 36.45 NiO, 12.15 FeO, 17.55 Fe₂O₃, 23.78 H₂O, 13.01 Cl, −O=Cl₂ −2.94, total is 100.00. The empirical formula (Z = 6) is Ni_2.16Fe_0.75²⁺Fe_0.97³⁺Cl_1.62(OH)_7.10 · 2.28H₂O. The simplified formula is Ni₃Fe³⁺Cl(OH)₈ · 2H₂O. Droninoite is trigonal, space group R $ \bar 3 $ \bar 3 m, R3m, or R32; a = 6.206(2), c = 46.184(18) Å; V = 1540.4(8) ų. The strong reflections in the X-ray powder diffraction pattern [d, Å (I, %) (hkl)] are 7.76(100)(006), 3.88(40)(0.0.12), 2.64(25)(202, 024), 2.32(20)(0.2.10), 1.965(0.2.16). The holotype specimen is deposited at the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow, registration number 3676/1.