Tooeleite, a new mineral from the U.S. Mine, Tooele County, Utah

Abstract

Abstract The new mineral tooeleite occurs with pyrite, arsenopyrite, scorodite, and jarosite at the U.S. Mine, Tooele Country, Utah. Analysis by electron microprobe gave Fe 2 O 3 43.56%, As 2 O 5 38.61%, SO 3 7.24%, and H 2 O by the Penfield method 9.80%. For this analysis, the suggested formula is Fe 8-2 x 3+ [(AS 1- x S x )O 4 ] 6 (OH) 6 .5H 2 0; x is about 0.2. Crystals are orthorhombic, perhaps Pbcm or Pbc 2 1 , with a = 6.416, b 19.45, c = 8.941 Å. The strongest diffraction lines are [ d in Å, (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; α = 1.94, β = 2.05, γ = 2.06. Hardness = 3, D meas = 4.23, D calc = 4.15 g/cm 3 for Z = 2.