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New data for iimoriite.

January 1, 1984

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.

Citation Information

Publication Year 1984
Title New data for iimoriite.
Authors E. E. Foord, M. H. Staatz, N. M. Conklin
Publication Type Article
Publication Subtype Journal Article
Series Title American Mineralogist
Series Number
Index ID 70013900
Record Source USGS Publications Warehouse
USGS Organization