Coldwellite, ideally Pd3Ag2S, is a new mineral species discovered in a heavy-mineral concentrate from the Marathon deposit, Coldwell Complex, Ontario Canada. It is cubic, crystallizing in space group P4332 (#212) with a 7.2470(8) Å, V 380.61(1) Å3, Z = 4. The five strongest lines of the X-ray powder-diffraction pattern [d in Å (I)(hkl)] are: 2.427(100)(221), 2.302(38)(310), 2.195(38)(311), 1.4280(44)(510,431), 0.9294(24)(650,643), and 0.9208(20)(732,651). Associated minerals in the discovery sample include Au-Ag alloy, hollingworthite, isoferroplatinum, keithconnite, kotulskite, mertieite-II, michenerite, palladoarsenide, sobolevskite, sperrylite, stillwaterite, vysotskite, Ti- and Cr-rich magnetite and ilmenite, pyrrhotite, chalcopyrite, and pentlandite, with trace amounts of bornite, cobaltite, and galena. Coldwellite is white with a light pinkish brown tint, and it has a metallic luster. No streak or microhardness could be measured. The mineral shows no internal reflections, pleochroism, bireflectance, or anisotropy. The reflectance values (%) in air for the standard COM wavelengths are: 41.9 (470 nm), 44.9 (546 nm), 44.0 (589 nm), and 45.0 (650 nm). The density, 9.90(1) g/cm3, was calculated using the empirical formula and the unit-cell parameters from the refined crystal-structure. The average result (n = 23) of electron-microprobe analyses is: Pd 56.1, Fe 0.16, Ag 38.2, S 5.63, total 100.09 wt.%, which corresponds to (Pd2.99Fe0.02)∑3.01Ag2.00S0.99, based on 6 apfu. The name recalls the type locality.
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Research Article|
September 01, 2015
Coldwellite, Pd3Ag2S, a New Mineral Species from the Marathon Deposit, Coldwell Complex, Ontario, Canada
Andrew M. McDonald
;
Andrew M. McDonald
*
Department of Earth Sciences, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6, Canada
*E-mail address:amcdonald@laurentian.ca
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Louis J. Cabri
;
Louis J. Cabri
Cabri Consulting Inc., 700-702 Bank Street, PO Box 14087, Ottawa, Ontario K1S 3V0, Canada
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Chris J. Stanley
;
Chris J. Stanley
Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom
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David J. Good
;
David J. Good
Department of Earth Sciences, University of Western Ontario, London, Ontario N5A 5B7, Canada
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Jason Redpath
;
Jason Redpath
Process Mineralogical Consulting Inc., 10630 240th Street, Maple Ridge, British Columbia V2W 2B2, Canada
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Geoff Lane
;
Geoff Lane
Process Mineralogical Consulting Inc., 10630 240th Street, Maple Ridge, British Columbia V2W 2B2, Canada
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John Spratt
;
John Spratt
Core Research Laboratories, Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom
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Doreen E. Ames
Doreen E. Ames
Geological Survey of Canada, 750-601 Booth Street, Ottawa, Ontario K1A 0E8, Canada
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The Canadian Mineralogist (2015) 53 (5): 845–857.
Article history
received:
16 Feb 2015
accepted:
15 Jul 2015
first online:
20 Nov 2017
Citation
Andrew M. McDonald, Louis J. Cabri, Chris J. Stanley, David J. Good, Jason Redpath, Geoff Lane, John Spratt, Doreen E. Ames; Coldwellite, Pd3Ag2S, a New Mineral Species from the Marathon Deposit, Coldwell Complex, Ontario, Canada. The Canadian Mineralogist 2015;; 53 (5): 845–857. doi: https://doi.org/10.3749/canmin.1500020
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Index Terms/Descriptors
- arsenides
- bismuthides
- Canada
- chemical composition
- coexisting minerals
- Coldwell Complex
- crystal chemistry
- crystal structure
- Eastern Canada
- electron probe data
- formula
- lattice parameters
- metals
- michenerite
- new minerals
- Ontario
- optical properties
- palladium
- platinum group
- platinum minerals
- reflectance
- silver
- space groups
- sperrylite
- sulfides
- unit cell
- X-ray diffraction data
- kotulskite
- Marathon Deposit
- keithconnite
- isoferroplatinum
- hollingworthite
- palladoarsenide
- mertieite
- stillwaterite
- sobolevskite
- vysotskite
- coldwellite
Latitude & Longitude