TOOELEITE, A NEW MINERAL FROM THE UNITED-STATES MINE, TOOELE COUNTY, UTAH

The new mineral tooeleite occurs with pyrite, arsenopyrite, scorodite, and jarosite at the U.S. Mine, Tooele Country, Utah. Analysis by electron microprobe gave Fe2O3 43.56%, As2O5 38.61%, SO3 7.24%, and H2O by the Penfield method 9.80%. For this analysis, the suggested formula is Fe-8 -2x(3+)[AS1-xSx)O4]6(OH)6.5H2O; x is about 0.2. Crystals are orthorhombic, perhaps Pbcm or Pbc2(1), with a = 6.416, b 19.45, c = 8.941 angstrom. The strongest diffraction lines are [d in angstrom, (hkl), (I)] 9.75 (020) (10); 3.208 (200,132) (9); 3.047 (061, 220) (5); 4.476 ({002) (4) and 2.680 (240,113) (4). The mineral is optically negative with a small 2V-; alpha = 1.94, beta = 2.05, gamma = 2.06. Hardness = 3, D(meas) = 4.23, D(calc) = 4.15 g/cm3 for Z = 2.