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Vaughanite, TlHgSb4S7, a new mineral from Hemlo, Ontario, Canada1

Published online by Cambridge University Press:  05 July 2018

Donald C. Harris
Affiliation:
Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, Canada K1A 0E8
Andrew C. Roberts
Affiliation:
Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, Canada K1A 0E8
Alan J. Criddle
Affiliation:
Department of Mineralogy, British Museum (Natural History), Cromwell Road, London, England, SW7 5BD

Abstract

Vaughanite, idealized formula T1HgSb4S7, is a very rare primary constituent of the Golden Giant orebody of the Hemlo gold deposit, Hemlo, Ontario, Canada. It was found in two polished sections from one drill core; as a 450 by 300 µm aggregate associated with pääkkönenite, stibnite, realgar, and native arsenic; and as a 40 µm anhedral grain associated with stibarsen and chalcostibite. Vaughanite is opaque with a metallic lustre and a black streak. No cleavage was observed but parting, produced by indentation, was detected as a series of weak parallel traces. It is brittle, with an even, occasionally arcuate, fracture. VHN25 is 100–115, mean 104. Mohs hardness (calc.) = 3−3½. In refected plane-polarized light in air the bireflectance is weak to moderate; the pleochroism is also weak, from a somewhat greenish grey to slightly darker bluish grey. Anisotropism is moderate to strong, with rotation tints in shades of green, yellow, purplish brown to brown. Reflectance spectra and colour values are tabulated. The colour in air is light grey. Internal reflections are rare but are arterial-blood-red on indentation fractures. X-ray studies have shown that vaughanite is triclinic with refined unit-cell parameters a 9.012 (3), b 13.223 (3), c 5.906 (2) Å, α 93.27 (3)°, β 95.05 (4)°, γ 109.16 (3)°, V 659.46 (80) Å3, a:b:c = 0.6815 : 1 : 0.4466 and Z = 2. The space group choices are P1 (1) or (2), diffraction aspect P*. The five strongest lines in the X-ray powder pattern [d in Å (l) (hkl)] are: 4.343 (30) (), 4.204 (100) (), 3.313 (60) (130), 2.749 (40) (, 131) and 2.315 (30) (, 122). The average of five electron microprobe analyses gave T1 18.3 (2), Hg 17.5 (2), Sb 43.4 (3), As 1.1 (1), S 20.5 (5), total 100.8 wt. %, corresponding, on the basis of total atoms = 13, to T10.98Hg0.95(Sb3.90As0.17)Σ4.07S7.00. The calculated density is 5.56 g/cm3 for the empirical formula and 5.62 g/cm3 for the simplified formula. The mineral is named for Professor David J. Vaughan.

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1989

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References

Criddle, A. J., Stanley, C. J., Chisholm, J. E., and Fejer, E. E. (1983) Henryite, a new copper-silver telluride from Bisbee, Arizona. Bull. Mineral. 106, 511-7.Google Scholar
Criddle, A. J., Stanley, C. J., Chisholm, J. E., and Fejer, E. E. (1986) QDF 2.94, Cylindrite. In The Quantitaire Data File for Ore Minerals (Criddle, A. J. and Stanley, C. J., eds.) 2nd iss. British Museum (Natural History).Google Scholar
Harris, D. C. (1986a) The minerals in the main Hemlo gold deposit, Ontario. Current Research, Part A, Geol. Survey of Canada, Paper 86-1A, 49-54.CrossRefGoogle Scholar
Harris, D. C. (1986b) Mineralogy of the main Hemlo gold deposit. In The Hemlo gold deposits, Ontario (Harris, D. C., ed.). Geological Association of Canada, Mineralogical Association of Canada, Canadian Geophysical Union, Joint Annual Meeting, Ottawa ’86, Field Trip 4: Guidebook, 74 pp. Also in Gold ”86 Excursion Guidebook: Toronto, 1986 (Pirie, J. and Dowries, M. J., eds.), 158-65.CrossRefGoogle Scholar
Harris, D. C. (1986c) Mineralogy and geochemistry of the main Hemlo gold deposit, Hemlo, Ontario, Canada. In Proceedings of Gold ’86, an International Symposium on the Geology of Gold, Toronto, 1986 (Macdonald, A. J., ed.), 297-310.Google Scholar
Harris, D. C., Roberts, A. C., Laflamme, J. H. G., and Stanley, C. J. (1988) Criddleite, T1AgzAu3SbloS10, a new gold-bearing mineral from Hemlo, Ontario, Canada. Mineral. Mag. 52, 691-7.CrossRefGoogle Scholar
Simpson, P. R. (1986) QDF 2.350, Stibnite (1975). In The Quantitative Data File for Ore Minerals (Criddle, A. J. and Stanley, C. J., eds.) 2nd iss. British Museum (Natural History).Google Scholar