Greenockite and zincian greenockite in epithermal polymetallic AgAuTe mineralization, Tinos Island, Hellas: Description and conditions of formation

Tombros, Stylianos; Seymour, Karen St.; Spry, Paul G.; Williams‐Jones, Anthony E.

doi:10.1127/0077-7757/2005/0024

Cited by 11 publications

(17 citation statements)

References 18 publications

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“…The EPMA data indicated that zincian greenockite contains 72.4-89.9 mol % CdS, which was in accordance with the experimental data of the ZnS-CdS system at 250 °C [7], and furthermore, the composition and structure were in line with the greenockite series [45] (cited in [2]). The Zn content varied (5.61 to 21.7 mol % ZnS), similarl to other occurrences of greenockite in hydrothermal deposits [4,11], e.g., 6-11 mol % ZnS in the Madjarovo Pb-Zn deposit [21], the maximum difference Figure 11. Compositions of cobaltite in the system of CoAsS-FeAsS-NiAsS, mol % (after [44]).…”

Section: Factors Influencing Composition Of Zincian Greenockitementioning

confidence: 79%

“…The experimental and natural assemblage data indicated that the zincian greenockite composition was influenced by the chemical composition of the ore fluid (e.g., the Zn/Cd ratio and possibly Cl − content [4]) and the physicochemical parameters (pH, fS2, fO2, aH2S) [4,7,42], of which temperature was most important. Fluid inclusion microthermometric data were obtained in previous studies [29,37,43]; however, the temperature of the sulfide-sulfosalt stage containing the zincian greenockite was not attained, due to the varying divisions of the different mineralization stages by different researchers [29,37,43].…”

Section: Factors Influencing Composition Of Zincian Greenockitementioning

confidence: 99%

“…However, greenockite also occurs as a primary mineral in various geological settings [4,11,12], including (i) pegmatites [13], (ii) granites [14], (iii) fumaroles [2], (iv) chromite-PGE mineralization [12], (v) hydrothermal ore deposits [4,11], (vi) estuarine sediments [15,16], and (vii) shales [17]. The predominant occurrences of greenockite in hydrothermal deposits are in Pb-Zn deposits, such as sediment-hosted Pb-Zn deposits [18,19], volcanic-related Pb-Zn deposits [20][21][22], as well as a few in orogenic Au deposits [23] and epithermal Au-Ag deposits [4,24]. Its existence is yet to be reported in skarn deposits.…”

Section: Introductionmentioning

confidence: 99%

“…Experimental studies of the system ZnS-CdS have indicated the existence of a complete solid solution at temperatures above 600 • C [4][5][6][7][8][9][10]. It has been shown that the solid solution exists to an extent at hydrothermal conditions below 400 • C [4], and that the replacement of Cd by Zn is a rather complicated process that is dependent on the formation environment [11].…”

Section: Introductionmentioning

confidence: 99%

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A New Zincian Greenockite Occurrence in the Saishitang Cu Skarn Deposit, Qinghai Province, Northwest China

Liu

Shu-gen

2017

Minerals

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Zn-Cd-S series minerals not only comprise industrial resources for Zn and Cd, but are also significant mineralogical indicators for hydrothermal ore-forming processes. Due to its unique formation conditions and rare occurrence, our understanding of the formation of zincian greenockite in natural systems is limited. Zincian greenockite was discovered during mineralogical studies in the Saishitang Cu skarn deposit, Qinghai Province, Northwest China. This provided an ideal opportunity to assess the occurrence and formation of zincian greenockite in skarn-type deposits. Ore minerals were observed using reflected-light microscopy, and the zincian greenockite was further analyzed using electron-probe microanalysis (EPMA) and X-ray diffraction (XRD). The zincian greenockite occurs in the bornite-chalcopyrite ores and is composed of subhedral to anhedral grains approximately 50 × 150 µm 2 to 200 × 300 µm 2 in size, replaces the bornite, and is replaced by native silver. Two phases (I and II) were identified based on back-scattered electron images, X-ray element-distributions maps, and EPMA data. The textural relationship indicated that Phase I was replaced by Phase II. Phase I contained high Zn (14.6 to 21.7 mol % ZnS) and low Cd (72.4 to 82.2 mol % CdS), while Phase II contained low Zn (5.6 to 9.1 mol % ZnS) and high Cd (85.4 to 89.9 mol % CdS). The zincian greenockite was formed at temperature of 300~270 • C during the transformation from a reducing environment to an oxidizing one in the late stage of the mineralization process in the Saishitang deposit.

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Section: Factors Influencing Composition Of Zincian Greenockitementioning

confidence: 79%

Section: Factors Influencing Composition Of Zincian Greenockitementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A New Zincian Greenockite Occurrence in the Saishitang Cu Skarn Deposit, Qinghai Province, Northwest China

Liu

Shu-gen

2017

Minerals

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“…Experimental studies have showed that magnesium has the capacity to increase the rate of hydrogen dissociation, slow down its adsorption kinetics, and lead hydrogen-bearing gases to condense (Swartz et al 1999). This hypothesis is supported by the presence of magnesium minerals in the most studied Ag-Au-Te ore deposits such as: dolomite-talc-brucite (Panormos Bay; Tombros et al 2004Tombros et al , 2005Tombros et al , 2007, Mg-chlorite (Acupan; Cooke et al 1996;Cooke and McPhail (2001), dolomite (Cripple Creek; Thompson et al 1985;Kelley et al 1998), dolomite and Mg-chlorite (Emperor, Tuvatu; Ahmad et al 1987;Scherbarth and Spry 2006), roscoelite and dolomite (Porgera; Richards and Kerrich 1993;Ronacher et al 2004) and Mg-chlorite and manganese ores (Sunnyside mine; Casadevall and Ohmoto 1977).…”

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confidence: 73%

Later stages of evolution of an epithermal system: Au–Ag mineralizations at Apigania Bay, Tinos Island, Cyclades, Hellas, Greece

et al. 2008

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Precious metals accompany all types of epithermal deposits. In general, the largest of these deposits occur in intrusive or extrusive rocks of alkaline or calc-alkaline affinity. The Apigania Bay vein system and Au-Ag mineralization is hosted in Mesozoic marbles and schists, and is composed primarily of five nearly parallel, high-angle quartz veins that extend for at least 200 m. Gold-silver mineralization, in association with more than thirty ore and vein minerals, is developed in three stages and occurs at the contact of marbles and schists. Zones of epidote-chlorite-calcite and sericite-albite alteration are associated with precious metal-bearing milky and clear quartz veins. Fluid inclusion studies suggest that hydrothermal mineralization was deposited under hydrostatic pressures of~100 bars, at temperature of 120-235°C, from low to moderate, calcium-bearing, saline fluids of 0.2 to 6.8 equiv. wt.% NaCl. Calculated isotope compositions (δ 18 O=−4.7‰ to 1.7‰ and δD= −120‰ to −80‰) for waters in equilibrium with milky and clear quartz are consistent with mixing with dilute, low temperature meteoric ore fluids. Calculated δ 13 C CO2 (0.6‰ to 1.1‰) and δ 34 S H2S (−7.3 to −0.3‰) compositions of the ore fluids indicate exchange, in an open system, with a metasedimentary source. Gold and silver deposition was associated with degassing of hydrogen due to intense uplift of the mineralizing area. The physicochemical conditions of mineralization stages I to III range between 200°C and 150°C, f S 2 ¼ 10

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Genesis of greenockite (CdS) and associated sulphide‐gold mineralization from Mahakoshal belt, Central Indian Tectonic Zone

et al. 2023

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The Zn‐Cd‐S critical minerals system is a significant mineralogical indicator of hydrothermal ore‐forming processes. The understanding of greenockite (CdS) formation in natural mineral systems is very restricted due to low crustal abundances (Cd <0.2 ppm). We report the first occurrence of greenockite from the Bagada orogenic gold prospect, Paleoproterozoic Mahakoshal belt, Central Indian Tectonic Zone (CITZ). This provides an ideal opportunity to access the occurrence and its genesis. Greenockite occurs in discrete sheared quartz veins hosted in phyllites. Sulphide mineralization is closely associated with hydrothermal chlorite alterations. Pyrrhotite, arsenopyrite, pyrite, and chalcopyrite assemblages are formed at high temperatures, while sphalerite and galena precipitated when the temperature decreased. Greenockite, native silver and bismuth with gold precipitated during the breakdown of arsenopyrite to scorodite in progressively oxidizing conditions. Greenockite precipitation occurred in a transforming hydrothermal environment from a reducing to an oxidizing one during late‐stage hydrothermal alteration. Sphalerite and chlorite thermometry yielded temperatures in the range from 266 to 366°C for this late‐stage hydrothermal alteration. Textural relations show two modes of occurrence of greenockite, one (Gck‐1) as exsolution within sphalerite (Sp‐2) and the other (Gck‐2) occurring as a discontinuous rim replacing the Cd‐rich sphalerite (Sp‐3). The Gck‐1 contains high Zn and low Cd, while as compared to Gck‐2. Zinc and Cd in greenockite show diadochy relation (Zn2+ ↔ Cd2+). Laser ablation ICPMS analyses of sphalerite (Sp‐2) reveal remarkably high Cd contents (1.9–12 wt%). Cd >0.02 ppm suggests possible Cd derivation from sphalerite (Sp‐2) under variable fS2, T, pH, fO2 conditions, fluid–rock interaction, and change in the Zn/Cd ratio. Sphalerite compositions display a low Zn/Cd (av.22) ratio and high temperature of formation, with characteristics intermediate between volcanogenic massive sulphides (VMS) and magmatic‐hydrothermal Cu‐Pb‐Zn system.

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Greenockite and zincian greenockite in epithermal polymetallic AgAuTe mineralization, Tinos Island, Hellas: Description and conditions of formation

Cited by 11 publications

References 18 publications

A New Zincian Greenockite Occurrence in the Saishitang Cu Skarn Deposit, Qinghai Province, Northwest China

A New Zincian Greenockite Occurrence in the Saishitang Cu Skarn Deposit, Qinghai Province, Northwest China

Later stages of evolution of an epithermal system: Au–Ag mineralizations at Apigania Bay, Tinos Island, Cyclades, Hellas, Greece

Genesis of greenockite (CdS) and associated sulphide‐gold mineralization from Mahakoshal belt, Central Indian Tectonic Zone

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