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TitleMiessiite, Pd11Te2Se2, a new mineral species from Miessijoki, Finnish Lapland, Finland
AuthorKojonen, K K; Tarkian, M; Roberts, A C; Törnroos, R; Heidrich, S
SourceCanadian Mineralogist vol. 45, no. 5, 2007 p. 1221-1227,
Alt SeriesEarth Sciences Sector, Contribution Series 20070476
PublisherMineralogical Association of Canada
Mediapaper; on-line; digital
File formatpdf (Adobe Reader)
AreaMiessijoki River; Lemmenjoki; Finnish Lapland; Finland
Lat/Long WENS 68.4000 68.4333 25.3667 25.3333
Subjectsmineralogy; palladium; tellurides; tellurium; selenium; crystallography; morphology, crystal; optical properties; chemical analysis; x-ray diffraction analyses; powder diffraction; reflectance; mineral occurrences; heavy minerals; mineral associations; placer deposits; gold; glacial deposits; glaciofluvial deposits; gravels; sands; terraces; tills; source rocks; granulites; granitic rocks; miessiite; physical properties; new mineral; platinum group elements; selenides; electron microprobe analyses
Illustrationslocation maps; tables; photomicrographs; graphs
AbstractTarkianite, a new mineral species of ideal composition (Cu,Fe)(Re,Mo)4S8, was recently discovered in sulfide concentrate from the Hitura Ni-Cu-PGE mine, Nivala, western central Finland. It is associated with pyrrhotite, pentlandite, valleriite, chalcopyrite, cubanite, mackinawite, chromite, and the PGE minerals sperrylite, michenerite, irarsite, froodite and hollingworthite. It is black, opaque with a metallic luster, a black streak, and is brittle with an irregular fracture. VHN15 is in the range 537-584, which corresponds to a Mohs hardness of 5½ to 6. Under reflected plane-polarized light, the mineral is light brown-gray and isotropic. The CIE color values (illuminant C) are: x 0.314 (air), 0.315 (oil); y 0.321 (air), 0.323 (oil) Y: 38.9 (air), 21.7 (oil); lamda-d: 575 (air), 573 (oil); Pe%: 2.1 (air), 3.2 (oil). The measured values of reflectance in air and oil for a single grain, respectively, are 38.02, 20.91 (470 nm), 37.87, 21.76 (546 nm), 39.18, 21.84 (589 nm), 39.30, 22.12 (650 nm) and values for 400-700 nm are tabulated. Tarkianite is cubic, F43m (by analogy with the synthetic equivalent), with unit-cell parameter refined from powder data: a 9.563(1) Å, V 874.5(1) Å3, Z = 4. The strongest eight lines of the X-ray powder-diffraction pattern [d in Å (I)(hkl)] are: 5.531(100)(111), 2.885(90)(311), 2.389(90)(400), 2.194(70)(331), 1.952(60)(422), 1.841(90)(511), 1.690(80)(440) and 1.246(50)(731). D (calc.) is 7.30 g/cubic cm (for the empirical formula and unit-cell parameter). Averaged electron-microprobe data yielded Re 53.61, Mo 12.32, Cu 5.48, Os 0.84, Fe 0.59, Ni 0.09, Co 0.08, S 26.77, total 99.78 wt.%, corresponding to (Cu0.83Fe0.10Ni0.02Co0.01)sigma-0.96(Re2.79Mo1.22Os0.04)sigma-4.03S8.01, based on a total of thirteen atoms. The mineral name honors Professor Mahmud Tarkian, of the University of Hamburg, Germany, for his contributions to ore mineralogy.