Girdite, oboyerite, fairbankite, and winstanleyite, four new tellurium minerals from Tombstone, Arizona

Abstract

SummaryGirdite, H2Pb3(TeO3)TeO6 is white, H = 2, D = 5.5. Crystals are complexly twinned and appear monoclinic domatic. The X-ray cell is a = 6.241Å, b = 5.686, c = 8.719, β = 91°41′; Z = 1.Oboyerite is H6Pb6(TeO3)3(TeO6)2 · 2H2O. H = 1.5, D = 6.4. Crystals appear to be triclinic but are too small for X-ray work.Fairbankite PbTeO3 is triclinic a = 7.81Å, b = 7.11, c = 6.96, α = 117°12′, β = 93°47′, γ = 93°24′, Z = 4. Indices are α = 2.29, β = 2.31, γ = 2.33.Winstanleyite, TiTe3O8, is cubic Ia3, a = 10.963Å. Crystals are cubes, sometimes modified by the octahedron; colour Chinese yellow, H = 4, nD = 2.34.All of the above species were found in small amounts on the waste dumps of the Grand Central mine, Tombstone, Arizona, associated with a wealth of other tellurites and tellurates.