A ferric iron equivalent of hematolite from Sterling Hill, New Jersey and Långban, Sweden

Abstract

AbstractAn unnamed Fe3+analogue of hematolite is described from Sterling Hill, New Jersey and Långban, Sweden. Eight microprobe analyses are in good agreement with ratios derived from a prior analysis which yielded: Al2O30.24, Fe2O310.85, MgO 10.61, MnO 41.76, As2O36.65, As2O515.29, H2O 13.23 (rem. = 1.63), sum = 100.26 %. Single-crystal study indicated that this compound is hexagonal witha= 8.28 Å, but the value ofccould not be well-defined due to complex polytypism giving rise to diffuse and poorly resolved reflections alongc*. In one case, a value ofc= 72.69 Å was dominant. All values that could be determined were multiples of approximately 12 Å. The strongest lines in the X-ray powder diffraction pattern are: 2.400(100), 1.563(100), 6.09(80), 3.42(50), and 5.13(50). This compound is dark red and occurs as platy hexagonal crystals in clusters associated with a wide variety of species in varied assemblages. It remains unnamed because of the ambiguity arising from polytypism.