The new mineral currierite (IMA2016-030), Na4Ca3MgAl4(AsO3OH)(12)center dot 9H(2)O, was found at the Torrecillas mine, Iquique Province, Chile, where it occurs as a secondary alteration phase in association with anhydrite, canutite, chudobaite, halite, lavendulan, magnesiokoritnigite, quartz, scorodite and torrecillasite. Currierite occurs as hexagonal prisms, needles and hair-like fibres up to similar to 200 mu m long, in sprays. The crystal forms are {100} and {001}. Crystals are transparent, with vitreous to silky lustre and white streak. The Mohs hardness is similar to 2, tenacity is brittle, but elastic in very thin fibres, and the fracture is irregular. Crystals exhibit at least one good cleavage parallel [001]. The measured density is 3.08(2) g cm(3) and the calculated density is 3.005 g cm(3). Optically, currierite is uniaxial () with omega = 1.614(1) and epsilon = 1.613(1) (measured in white light). The mineral is slowly soluble in dilute HCl at room temperature. The empirical formula, determined from electron-microprobe analyses, is (Na(3.95)Al(2.96)Ca(2.74)Mg(1.28)fe(0.63)(3+)Cu(0.13)K(0.08)Co(0.03))Sigma(11.80()AS(11.68)(5+)Sb(0.32)(5+) Sigma(12)(O56.96Cl0.04)Sigma H-57(30.81). Currierite is hexagonal, P622, with a = 12.2057(9), c = 9.2052(7) angstrom, V = 1187.7(2) angstrom(3) and Z = 1. The eight strongest powder X-ray diffraction lines are [d(obs) angstrom(I)(hkl)]: 10.63(100)(100), 6.12(20)(110), 5.30(15)(200), 4.61(24)(002), 4.002(35)(210), 3.474(29)(202), 3.021(96)(212) and 1.5227(29)(440,334,612). The structure of currierite (R-1 = 2.27% for 658 F-o > 4 sigma F reflections) is based upon a heteropolyhedral chain along c in which AlO6 octahedra are triple-linked by sharing corners with AsO3OH tetrahedra. Chains are linked to one another by bonds to 8(4 + 4)-coordinated Na and 8-coordinated Ca forming a three-dimensional framework with large cavities that contain rotationally disordered Mg(H2O)(6) octahedra. The chain in the structure of currierite is identical to that in kaatialaite and a geometrical isomer of that in ferrinatrite. The mineral is named in honour of Mr. Rock Henry Currier (19402015), American mineral dealer, collector, author and lecturer.