Phosphogartrellite, PbCuFe(PO4)2(OH)•H2O, a new member of the tsumcorite group

Phosphogartrellite is associated with hentschelite, pyromorphite, malachite, and cuprite on samples from Hohenstein (type locality) and Gadernheim, Odenwald, Germany. The new mineral forms aggregates (up to 0.2 mm) and very small individual crystals (<50 mu m). The colour is bright green, the streak is yellow and the Mohs' hardness is 4 1/2. Phosphogartrellite is biaxial positive, 2V(z) = 70 (5)degrees, n(alpha) = 1.90(2), n(beta) = 1.93(calc.), and n(gamma) = 2.00(2). Electron microprobe investigation gave PbO 39.02, CaO 0.20, Fe2O3 14.14, CuO 14.41, P2O5 22.05, As2O5 4.58, H2O (calc.) 4.83, sum 99.23 wt.-%. The empirical formula based on 10 oxygen atoms is Pb0.99Ca0.02Cu1.02Fe1.00(PO4)(1.75)(AsO4)(0.23)(OH)(1.12)(H2O)(0.96); the idealized formula is PbCuFe(PO4)(2)(OH). H2O. The 6 strongest lines of the powder diffraction pattern are [d(hkl) in Angstrom, (I-obs) (hkl)]: 4.720(67) (011), 4.502(61) (101), 4.360(100) (111), 3.250(70) (012), 2.885(89) (11 (1) over bar), 2.868(69) (1 (1) over bar (1) over bar). Unit cell parameters were calculated from the powder diffraction data. By analogy with gartrellite, phosphogartrellite is triclinic, space group P (1) over bar, with a = 5.320(2), b = 5.528(2), c = 7.434(3) Angstrom, alpha = 67.61(3)degrees, beta = 69.68(5)degrees, gamma = 70.65(4)degrees, V = 184.5 Angstrom(3), Z = 1, D-x = 5.05 g/cm(3). Phosphogartrellite is the phosphate analogue of gartrellite.