... to American Mineralogist , Oct. 11 , 2001 . Nickel, E.H. ( 1968 ) Structural stability of minerals with the pyrite, marcasite, arsenopyrite and loellingite structures. Canadian Mineralogist , 9 , 311 –321. Pearson, W.B. ( 1965 ) Compounds with the marcasite structure. Zeitschrift für...

... alteration facies, whereas the inner parts comprise an illite-siderite and/or pyrite (pyrrhotite) alteration facies accompanied by quartz near the feeder conduit. Transition between the two facies is gradational. The economic gold-bearing arsenopyrite, associated with rare pyrrhotite, loellingite, pyrite...

..., pyrite, and minor scheelite and orthoclase. The earliest retrograde mineralization consists of arsenopyrite (stages II and III), which contains variable amounts of Co, together with native Bi (±bismuthinite) and Au, with lesser magnetite, marcasite, pyrite, hastingsite, and minor quartz. The preservation...

... –10 −24 bar (1 bar = 100 kPa), based on the assemblage magnetite + ilmenite + olivine in calcite-rich prograde skarn. The sulphur fugacity of the fluid is estimated at 10 −7 –10 −9 bar, based on the assemblages pyrrhotite + loellingite, pyrrhotite + arsenopyrite and pyrite + marcasite, which were...

... stockwork and dissemination in a calc-alkaline tonalite stock (1.89–1.88 Ga) (see Fig. 1 ). The major ore minerals are chalcopyrite, arsenopyrite, pyrrhotite; the minor ones are loellingite, marcasite, pyrite, sphalerite, gold, molybdenite, cubanite, bornite, stannite, bismuth and several Bi-bearing...

... radiation X-ray photoelectron spectroscopy (SRXPS) study . Vacuum , 202 , 1 – 8 , https://doi.org/10.1016/j.vacuum.2022.111151 . Harmer , S.L. and Nesbitt , H.W. ( 2004 ) Stabilization of pyrite (FeS 2 ), marcasite (FeS 2 ), arsenopyrite (FeAsS) and loellingite (FeAs 2 ) surfaces...

... 1993 for review). The transition metal disulfides containing S-S (and S-As or As-As) dimers exist in four principal structure-types characterized by pyrite, marcasite, arsenopyrite and loellingite (see Makovicky 2006 ). In each of these structures the metals are octahedrally coordinated to six anions...

... into particles of native gold within structurally deeper ores. However, Oberthür et al. (1997) also investigated gold ores from the Ashanti Belt and found gold in two ore types: free-milling gold in quartz veins and refractory sulphide ores (arsenopyrite + pyrite ± pyrrhotite ± marcasite) containing...

... gas . Physical Review B , 136 , 864 – 871 . Huggins M.L. ( 1922 ) The crystal structures of marcasite (FeS 2 ), arsenopyrite (FeAsS) and loellingite (FeAs 2 ) . Physical Review , 19 , 369 – 373 . Hulliger F. Mooser E. ( 1965 ) Semiconductivity in pyrite...

... and, as explained presently, the more likely explanation for the asymmetry is the presence of additional Ni contributions to the high binding-energy side of the peak. GaAs, pyrite, marcasite, and arsenopyrite are semiconductors (not conductors), hence their spectral peaks do not have a Doniach-Sunjic...

...F igure 1 Crystal structures of the major sulfides. ( A ) Galena (PbS). ( B ) Sphalerite (ZnS). ( C ) Wurtzite (ZnS). ( D ) Niccolite (NiAs). ( E ) Linkage of metal–sulfur octahedra along the c -axis direction in pyrite (FeS 2 ), marcasite (FeS 2 ), loellingite (FeAs 2 ) and arsenopyrite (FeAsS...

... and related minerals. Physics and Chemistry of Minerals , 11 , 75 –80. Tossell, J.A., Vaughan, D.J., and Burdett, J.K. ( 1981 ) Pyrite, marcasite, and arsenopyrite type minerals: Crystal chemical and structural principles. Physics and Chemistry of Minerals , 7 , 177 –184. Vaughan, D.J. and Rosso...

... spectroscopic study of the adsorption of Ni(II) on pyrite and arsenopyrite at pH 10 . Surf. Interface Anal ., 27 , 9 , 849 – 860 . Harmer , S.L. & Nesbitt , H.W. ( 2004 ): Stabilization of pyrite (FeS 2 ), marcasite (FeS 2 ), arsenopyrite (FeAsS) and loellingite (FeAs 2 ) surfaces...

... . Harmer , S.L. & Nesbitt , H.W ( 2004 ): Stabilization of pyrite (FeS 2 ), marcasite (FeS 2 ), arsenopyrite (FeAsS) and loellingite (FeAs 2 ) surfaces by polymerization and auto-redox reactions . Surf. Sci . 564 , 38 – 52 . ———, Pratt , A.R. , Nesbitt , H.W. & Fleet...

...]. Sulfur, like arsenic, in stable elemental form forms polymeric units, sulfur forming 8-membered rings and arsenic puckered 4-membered rings ( Cotton and Wilkinson 1988 ). Sulfur at S-terminated surfaces of marcasite, and arsenic at As-terminated surface of loellingite form surface polymeric species...

... was developed in the following sequence: Pyrite, arsenopyrite, and marcasite were deposited at the early stage, next were Pb, Zn, and Cu sulfides; at the late stage, native gold, pyrargyrite, stephanite, proustite, minerals of the pearceite–polybasite series, acanthite, and other Ag minerals were deposited...

... sulfides, which locally are very abundant, are pyrrhotite, arsenopyrite, pyrite, sphalerite, and galena. In addition, hematite, marcasite, bismuthinite, and native bismuth have also been observed. The main gangue minerals are quartz, chlorite, and fluorite. The minerals that formed during the sulfide stage...

... vein Gersdorffite BIE-448a Bieber, not further specified Skutterudite, native bismuth BIE-452a University of Karlsruhe Tennantite, skutterudite, marcasite, pyrite BIE-456 University of Stuttgart Cobaltite, safflorite, loellingite, skutterudite BIE-457 University of Karlsruhe Native...

... for the pristine arsenopyrite surface has been facilitated by comparative studies of related dianion species and by the use of SXPS. In particular, Harmer and Nesbitt (2004) have compared Fe 2 p , S 2 p and As 3 d spectra of pyrite, marcasite, arsenopyrite and loellingite and proposed auto-redox...