Pyrrhotite 8-quartz

Iriki fahore, gold-fieldite, native tellurium fahore, famatinite argentite, chalcopyrite, fabore, famatinite, arsenopyrite, marcasitc, pyrite, pyrrhotite quartz, kaolinite, anatase... 

The Renison Bell tin mine is a large, but complex, oxide mineral deposit. Renison ore consists largely of pyrrhotite, quartz, dolomite, siderite and dorite. The chemical composition of the iron varies considerably. Some of the ore types are high in copper and silver. Table 21.5 shows the chemical analyses of various ore types. 

Yatani argentite electrum, chalcopyrite, marcasite, pyrite, pyrrhotite, galena, sphalerite quartz, adularia, chlorite, sericite, rhodochrosite... 

Occurrence of pyrrhotite, arsenopyrite and high iron content of sphalerite indicate low fs,2 and /02 conditions. Decrepitation temperatures of fluid inclusions in quartz from Sn-Cu-As stage are 403-322°C (Enjoji and Takenouchi, 1976). 

Main opaque minerals include native gold, electrum, pyrite, pyrrhotite, chalcopy-rite, cubanite, sphalerite, arsenopyrite and tellurobismutite. The amounts of these sulfide minerals are poor, compared with those in epithermal Au-Ag vein-type deposits. It is noteworthy that silver minerals are abundant in epithermal Au-Ag vein-type deposits, whereas they are poor in gold-quartz veins. 

The veins are composed mostly of quartz and a small amount of sulfide minerals (pyrite, pyrrhotite, arsenopyrite, chalcopyrite, sphalerite, and galena), carbonate minerals (calcite, dolomite) and gold, and include breccias of the host rocks with carbonaceous matters. Layering by carbonaceous matters has been occasionally observed in the veins. Banding structure, wall rock alteration and an evidence of boiling of fluids that are commonly observed in epithermal veins have not been usually found. 

Main opaque minerals are chalcopyrite, pyrite, pyrrhotite, sphalerite and bornite (Table 2.22). These minerals commonly occur in massive, banded and disseminated ores and are usually metamorphosed. Hematite occurs in red chert which is composed of fine grained hematite and aluminosilicates (chlorite, stilpnomelane, amphibole, quartz) and carbonates. The massive sulfide ore bodies are overlain by a thin layer of red ferruginous rock in the Okuki (Watanabe et al., 1970). Minor opaque minerals are cobalt minerals (cobaltite, cobalt pentlandite, cobalt mackinawite, carrollite), tetrahedrite-tennantite, native gold, native silver, chalcocite, acanthite, hessite, silver-rich electrum, cubanite, valleriite , and mawsonite or stannoidite (Table 2.22). 

Whether the adsorption of molecules at the surface of minerals is a curse or a blessing for the adsorbed substances depends on many parameters. Experiments showed very different adsorption behaviour of adenine on different minerals. Active minerals are of particular importance for hydrothermal processes (see Sect. 7.2). The surface concentration of adenine on pyrites is fifteen times, that on quartz five times, and on pyrrhotite three and a half times as high as in a starting solution whose concentration is 20 pM (Cohn, 2002). 

In order to prepare standard mineral mixtures, pyrite (Py), pyrrhotite (Po), chalcopyrite (Cp), sphalerite (Sp), siderite (Sid), dolomite (Dol), calcite (Cal) and quartz (Qz) were acquired as pure mineral samples through a specialized distributor (Minerobec, Canada). These 8 pure minerals were further cleaned under a binocular microscope and separately crushed to reach 95% under 150pm (typical tailings grain size distribution e.g. Aubertin et al. 2002). Each pure mineral powder was characterized thereafter with a series of chemical and mineralogical techniques. More details can be found in Bouzahzah et al. (2008). The relative density of each mineral specimen were measured with an He pycnometer and are... 

The most important tin deposits are hydrothermal deposits (hypothermal and mesothermal). The magmatic deposits do not often contain tin mineralization. Tin may also be present in pegmatitic ore bodies. However, tin found in pegmatitic deposits can be classified into two basic types (a) quartz-cassiterite lenses in granite, when cassiterite is associated with topaz, beryl and, to a lesser degree, sulphides (b) sulphide deposits, where tin is mainly cassiterite associated with arsenopyrite, pyrite, chalcopyrite and pyrrhotite. Such deposits are common in South America (Peru, Bolivia). 

In general, the run-of-mine ore is composed of quartz and silicates, 40-50%, and sulphides (pyrite, marcasite, pyrrhotite and arsenopyrite). The principal tin mineral is cassiterite, with minor amounts of stannite. Based on liberation studies, a large portion of the tin is liberated at 300-400 pm size. A portion of the tin is liberated at-12 pm size. The generalized gravity concentration flowsheet is shown in Figure 21.9. 

Mineralization was represented by quartz-chlorite-carbonate-sulfide veins with visible chalcopyrite, galena, sphalerite, pyrrhotite, cobaltite, limonite and malachite. Fractures filled by veins are identified on aerial photos as one submeridional zone up to 20 m thick and 500 m long. The northeastern linear system represented by a shear zone containing veinlets with arsenopyrite, bismuthine, gold and silver sulfosalts. Twelve veins that differ in extent and intensity of mineralization were discovered, with some veins yielding 3 wt. % Sn, 3 wt. % Cu, and up to 250 g/t Ag. 

The fault-fill mineralization includes quartz, dolomite, ankerite, siderite, calcite, molybdenite, pyrrhotite, arsenopyrite, pyrite, chalcopyrite, sphalerite, galena, selenian galena, marcasite, ilmenite, and rutile (Maanijou 2007). 

Pyrite has undergone variable degrees of recrystallization during metamorphism with porphyroblast development facilitated in sections with increased contents of pyrrhotite and gangue minerals (quartz and carbonate) in the matrix. Pyrrhotite and chalcopyrite exhibit extensive recrystallization and plastic flow features, with pyrrhotite-rich sections exhibiting durchbewegung textures. Pyrrhotite in the... 

Five different vein phases (Types i to V) are recognized at both deposits, aii have variabie amounts of carbonates and quartz gangue. Type i veins contain oniy brecciated quartz and carbonate minerals and at ED are spatially associated with disseminated arsenopyrite, chalcopyrite, pyrrhotite, and pyrite in the mafic host rock. Type II veins in both deposits are partly brecciated and contain 5-80% sulfides of dominantly pyrite, arsenopyrite, and at GB chalcopyrite. Type III veins are quartz-calcite-tetrahedrite-bismuthinite microveins that cut both Types I and II veins. The fine-grained sulfides replace and enclose arsenopyrite and pyrite in Type II veins and are also visible in microfractures within the Type II sulfides. Type IV veins are base-metal rich and characterized by galena, sphalerite, chalcopyrite, pyrite, and stibnite with a maximum width of 20 cm. The Type V veins are late barren-carbonate veins cutting all previous veins and textural features. 

The silicate facies is of a black finely laminated type, consisting mainly of magnetite with up to 15 vol. % grunerite and up to 5% carbonaceous matter. The facies is found in layers up to a few dm thick. Common to the silicate facies is the scarcity of quartz and the complete absence of carbonates. The sulphide facies of Isua consists of up to 60 vol. % sulphides (pyrite, pyrrhotite) together with grunerite or actinolite and magnetite (Appel, 1980) 118). 

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