Texasite, Pr2O2(SO4), occurs as a supergene alteration product of primary rare-earth minerals at the Clear Creek pegmatite, Burnet County, Texas, and at the Rode Ranch pegmatite. Llano County, Texas. Associated minerals include gadolinite, allanite, yttrofluorite, bastnaesite, behoite, rowlandite, tengerite, and chlorine-bearing jarosite. Crystals are small (0.1 mm), translucent, and apple-green in color. It is orthorhombic, space group Imm2 or 1222. The unit-cell constants are a = 4.139(5), b = 4.243(5), с = 13.431(15) A, Z = 2. The strongest lines in the X-ray powder pattern are 6.72(3)(002), 4.051(7)(011), 3.960(6)(101), 3.358(6)(004), 3.082(10)(013), 2.238(2)(006), and 1.980(2)(202). These are essentially identical with those of synthetic Pr2O2(SO4). Texasite is biaxial (–), 2V = 26-31°, with refractive indices α = 1.862(2), β = 1.917(2), γ= 1.921(2). Density (calc) is 5.769. The name is in honor of the state of Texas, the location of the Barringer Hill rare-earth pegmatite district.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not have access to this content, please speak to your institutional administrator if you feel you should have access.