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Mineralogical ClassificationIMA 2017-065 = meitnerite

8th Nov 2018 01:00 UTCMarco E. Ciriotti Manager

Reference:

▪ Kampf, A.R., Plášil, J., Nash, B.P., Marty, J. (2018): Meitnerite, (NH4)(UO2)(SO4)(OH)·2H2O, a new uranyl-sulfate mineral with a sheet structure. European Journal of Mineralogy, 30, 999-1006.

Abstract:

Meitnerite Q1 (IMA2017-065), (NH4)(UO2)(SO4)(OH)·2H2O, is a new mineral from the Green Lizard mine in Red Canyon, San Juan County, Utah, USA, where it occurs as a secondary alteration phase. It occurs on partially recrystallized quartz grains in association with beshtauite and gypsum. Meitnerite occurs as intergrowths of tabular crystals, flattened on {0 1 &1macr;}, up to about 80μm in diameter and 30 mμ thick. The mineral is slightly greenish yellow and transparent with a vitreous lustre and very pale yellow streak. It exhibits greenish-white fluorescence in 405 nm light. Crystals are brittle with irregular fracture, and a perfect cleavage on {0 1 &1macr;}. The Mohs’ hardness is ca. 2. The calculated density is 3.320 g·cm-3. At room temperature, the mineral is slowly soluble in H2O and very rapidly soluble in dilute HCl. Optically, meitnerite is biaxial (–), with α = 1.568(2), β = 1.589(2), γ = 1.607(2) (white light); 2V = 84(1)°. The dispersion is r > v, moderate, The optical orientation is X∧b=26°, Y∧a=15°, Z∧c=53°. The pleochroism is X nearly colourless, Z pale green yellow, Y light green yellow; X2σI], contains uranyl sulfate sheets based on the phosphuranylite anion topology. The interlayer region contains an NH)4)+ group and two H)2)O groups.

8th Nov 2018 18:42 UTCRonnie Van Dommelen 🌟 Manager

Updated mineral page, except for "The optical orientation is X∧b=26°, Y∧a=15°, Z∧c=53°."

9th Nov 2018 15:53 UTCUwe Kolitsch Manager

Ronnie: you can put that in "Optical Data (all minerals)" / "Comments".

9th Nov 2018 17:01 UTCRonnie Van Dommelen 🌟 Manager

Thanks Uwe. Done.