In its first reported occurrence outside of Japan, iimoriite, Y2(SiO4)(CO3), has been found in a thorite- and uraninite-bearing quartz and albite vein from Bokan Mountain on Prince of Wales Island, Alaska. It occurs as buff-tan subhedral and anhedral grains, 0.01-0.5 mm in diameter, with vitreous lustre, white streak, and H. 51/2-6. Colourless in thin section, with no pleochroism, iimoriite is biaxially negative with alpha 1.753, beta 1.824, gamma 1.830, 2Valpha (obs.) 31o, 2Valpha (calc.) 31.5o. The mineral is triclinic, space group P1 or P1, a 6.573(1), b 6.651(1), c 6.454(1) A, alpha 116.44, beta 92.34, gamma 95.63o, Z = 2, Dobs. 4.47, Dcalc. 4.56 (from Gladstone-Dale relationship), Dcalc. 4.91 (from calculated formula weight and cell volume) g/cm3. The strongest XRD lines are 2.88(100), 2.95(80), 2.78(40), 3.02(36), 2.84(35) A. Chemical analyses are tabulated. -J.A.Z.

American Mineralogist↗

USGS1983

Trace element analyses of tourmalines from Appalachian-Caledonian massive sulfide deposits

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Open-File Report↗

USGS1983

Cuprian fraipontite and sauconite from the Defiance-Silver Bill mines, Gleeson, Arizona.

XRD studies have shown the fine-grained, light blue-green mineral previously identified as turquoise or chrysocolla to be the rare species fraipontite + or - admixed sauconite. Composite microprobe and XRF analyses gave SiO2 24.8, Al2O3 17.3, CaO 0.34, CuO 5.2, ZnO 40.95, H2O (ign. loss, 900oC) 12.8, = 101.39, yielding the formula (Zn1.84Al0.77Cu0.24box 0.13- Ca0.02)3.00(Si1.51Al0.49)2.00O5(OH)4. Semiquantitative emission spectrographic analysis showed Fe 0.007, Mg 0.01, Ca 0.07, Si 10, Al major, Na 0.015, Zn major, Cu 5%; Mn 15, B 150, Be 7, Ni 50, Pb 15, Sc 15, Ga 70 and Ag 1 ppm. It has a 5.331(8), b 9.23(1), c 7.275(6) A, beta 104.15o; H. 3.5-4; Dcalc 3.44, Dobs. 3.08- 3.10; mean refr. ind. approx 1.61. Much of the fraipontite is admixed with sauconite, which may be forming from the fraipontite. XRF analysis of this material gave SiO2 32.8, Al2O3 10.9, MgO < 0.1, CaO 1.51, Na2O < 0.2, K2O < 0.02, TiO2 < 0.02, P2O5 < 0.02, MnO < 0.02, CuO 4.65, ZnO 39.9, ign. loss 13.9, = 103.7.-G.W.R.

Mineralogical Record↗

USGS1982

Stolzite from Tsumeb.

The world's largest known crystal of stolzite (1.3 X 1.3 X 2.5 cm) is described. It is associated with tennantite and quartz, and is from the Tsumeb mine, Tsumeb, Namibia. Forms present include (001), (111), (101), (122), and (212). Spectrographic analyses indicate a nearly end-member composition with Mo, Fe, Ba, Ca, and Mn present in trace amounts only. This stolzite fluoresces lemon- yellow and red in shortwave and longwave UV light, respectively.-G.W.R.

Mineralogical Record↗

USGS1976

Glass reference standards for the trace-element analysis of geological materials; compilation of interlaboratory data

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Professional Paper↗