Ferrotaaffeite-2N’2S, ideally BeFeb>3b>Alb>8b>Ob>16b> with hexagonal symmetry P6b>3b>mc, is a new mineral species of the taaffeite group (IMA No. 2011-025) occurring as a skarn mineral in the Xianghualing Sn-polymetallic ore field, Linwu County, Hunan Province, People’s Republic of China. It was found near the outer contact of the Laizhiling A-type granite pluton and in the Middle-Upper Devonian carbonate rocks of the Qiziqiao Formation. The associated minerals are Fe2+-rich magnesiotaaffeite-2N’2S, ferronigerite-2N1S, cassiterite, liberite, pyrite, sphalerite, pyrrhotite, galena, spinel, and phlogopite. The mineral forms tabular crystals about 100 μm in size. It is dark green to dark grey with a white streak, transparent, and has a vitreous lustre. Cleavage is fair on {001}. It is brittle, with a conchoidal fracture. The hardness is VHNb>50b> 1801–2404 kg/mm2 (8.5–9 on the Mohs scale). No fluorescence in long- or short-wave ultraviolet radiation was observed. The calculated density from the empirical chemical formula is 3.99 g/cm3. The Gladstone-Dale relationship gives Nb>calcb> = 1.82. The empirical formula for the investigated ferrotaaffeite-2N’2S is Be(Feb>1.39b>Mgb>0.97b>Znb>0.42b>Mnb>0.17b>Snb>0.03b>)b>∑2.98b>Alb>7.99b>Ob>16b>,. The simplified formula is Be(Fe,Mg,Zn)b>3b>Alb>8b>Ob>16b>. The strongest five reflections in the X-ray powder diffraction pattern [d in Å (I) hkl] are: 2.43(100) 114, 2.60(90) 016, 1.425(90)220, 2.86(80) 110, and 1.473(80) 0210. The unit-cell parameters refined from the powder data are a 5.706(8), c 18.352(3) Å, and V 517.46(8) Å3, Z = 2. The associated Fe2+-rich magnesiotaaffeite-2N’2S has empirical formula Be(Mgb>1.54b>Feb>0.98b>Znb>0.38b>Mnb>0.14b> Snb>0.02b>)b>∑3.06b>Alb>7.95b>Ob>16b>. Its structure was solved and refined in space group P6b>3b>mc, with a 5.6978(8), b 5.6978(8), c 18.373(4) Å, V 516.57(15) Å3, to Rb>1b> = 0.043, wRb>2b> = 0.137.
