Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Cabri, L. J. Articles by Rudashevsky, V. N. Search for Related Content GeoRef GeoRef Citation

Naldrettite, Pd₂Sb, a new intermetallic mineral from the Mesamax Northwest deposit, Ungava region, Québec, Canada

¹ Cabri Consulting Inc., 99 Fifth Avenue, Suite 122, Ottawa, Ontario, Canada K1S 5P5
² Department of Earth Sciences, Laurentian University, Ramsey Lake Road, Sudbury, Ontario, Canada P3E 2C6
³ Natural History Museum, Cromwell Road, London SW7 5BD, UK
⁴ Center for New Technologies, Roentgena Street 1, 197101, St. Petersburg, Russia
⁵ CANMET/MMSL, 555 Booth Street, Ottawa, Ontario, Canada K1A 0G1
⁶ Canadian Royalties Inc., 1176 Delnite Road, Timmins, Ontario, Canada P4N 7J8
⁷ Department of Geology, University of Toronto, 22 Russell St., Toronto, Ontario, Canada M5S 3B1

^* E-mail: lcabri{at}sympatico.ca

Naldrettite, Pd₂Sb, is a new intermetallic mineral discovered in the Mesamax Northwest deposit, Cape Smith fold belt, Ungava region, northern Québec. It is associated with monoclinic pyrrhotite, pentlandite, chalcopyrite, galena, sphalerite, cobaltite, clinochlore, magnetite, sudburyite (PdSb), electrum and altaite. Other rarer associated minerals include a second new mineral (ungavaite, Pd₄Sb₃), sperrylite (PtAs₂), michenerite (PdBiTe), petzite (Ag₃AuTe₄) and hessite (Ag₂Te). Naldrettite occurs as anhedral grains, which are commonly attached or moulded to sulphide minerals, and also associated with clinochlore. Grains of naldrettite vary in size (equivalent circle diameter) from ~10 to 239 µm, with an average of 74.4µm (n = 632). Cleavage was not observed and fracture is irregular. The mineral has a mean micro-indentation hardness of 393 kg/mm² It is distinctly anisotropic, non-pleochroic, has weak bireflectance, and does not exhibit discernible internal reflections. Some grains display evidence of strain-induced polysynthetic twinning. Naldrettite appears bright creamy white in association with pentlandite, pyrrhotite, clinochlore and chalcopyrite. Reflectance values in air (and in oil) for R₁and R₂ are: 49.0, 50.9 (35.9, 37.6) at 470 nm, 53.2, 55.1 (40.3, 42.1) at 546 nm, 55.4, 57.5 (42.5, 44.3) at 589 nm and 58.5, 60.1 (45.4, 47.2) at 650 nm. The average of 69 electron-microprobe analyses on 19 particles gives: Pd 63.49, Fe 0.11, Sb 35.75, As 0.31, and S 0.02, total 99.68 wt.%, corresponding to (Pd_1.995Fe_0.007)_2.002 (Sb_0.982As_0.014S_0.002)_0.998. The mineral is orthorhombic, space group Cmc2₁,a 3.3906(1), b 17.5551(5), c 6.957(2) A, V 414.097(3) ų, Z = 8. D_calc is 10.694(1) g/cm³. The six strongest lines in the X-ray powder-diffraction pattern [d in Å (I)(hkl)] are: 2.2454(100)(132), 2.0567(52)(043), 2.0009(40)(152), 1.2842(42)(115), 1.2122(50)(204) and 0.8584(56)(1.17.4).

KEYWORDS: PGE, PGM, naldrettite, Pd-Sb, new intermetallic mineral species, platinum-group elements, platinum-group minerals, hydroseparation, Mesamax Northwest deposit, Cape Smith fold belt, Québec, Ungava, Canada

This article has been cited by other articles:

				D. A. Holwell, I. McDonald, and P. E. B. Armitage Platinum-group mineral assemblages in the Platreef at the Sandsloot Mine, northern Bushveld Complex, South Africa Mineralogical Magazine, February 1, 2006; 70(1): 83 - 101. [Abstract] [Full Text] [PDF]

				A. M. McDonald, L. J. Cabri, C. J. Stanley, N. S. Rudashevsky, G. Poirier, J. E. Mungall, K. C. Ross, B. R. Durham, and V. N. Rudashevsky UNGAVAITE, Pd4Sb3, A NEW INTERMETALLIC MINERAL SPECIES FROM THE MESAMAX NORTHWEST DEPOSIT, UNGAVA REGION, QUEBEC, CANADA: DESCRIPTION AND GENETIC IMPLICATIONS Can Mineral, October 1, 2005; 43(5): 1735 - 1744. [Abstract] [Full Text] [PDF]