Solubility of gold in arsenian pyrite

Reich, Martín; Kesler, Stephen E.; Utsunomiya, Satoshi; Palenik, Christopher S.; Chryssoulis, Stephen L.; Ewing, Rodney C.

doi:10.1016/j.gca.2005.01.011

Cited by 778 publications

(574 citation statements)

References 41 publications

Supporting

Mentioning

459

Contrasting

Unclassified

Order By: Relevance

“…Furthermore, Stage 2B pyrite is significantly enriched in Au (average 56 ppm and up to 367 ppm) relative to Stage 2A pyrite (average 2.4 ppm and up to 11 ppm). This is consistent with previously made observations of high incorporation of Au in arsenian pyrite [68].…”

Section: Pyritesupporting

confidence: 94%

Mineralogical Distribution of Germanium, Gallium and Indium at the Mt Carlton High-Sulfidation Epithermal Deposit, NE Australia, and Comparison with Similar Deposits Worldwide

et al. 2017

View full text Add to dashboard Cite

Germanium, gallium and indium are in high demand due to their growing usage in high-tech and green-tech applications. However, the mineralogy and the mechanisms of concentration of these critical elements in different types of hydrothermal ore deposits remain poorly constrained. We investigated the mineralogical distribution of Ge, Ga and In at the Mt Carlton high-sulfidation epithermal deposit in NE Australia, using electron probe microanalysis and laser ablation inductively-coupled plasma mass spectrometry. Parageneses from which selected minerals were analyzed include: Stage 1 acid sulfate alteration (alunite), Stage 2A high-sulfidation enargite mineralization (enargite, argyrodite, sphalerite, pyrite, barite), Stage 2B intermediate-sulfidation sphalerite mineralization (sphalerite, pyrite, galena) and Stage 3 hydrothermal void fill (dickite). Moderate to locally high concentrations of Ga were measured in Stage 1 alunite (up to 339 ppm) and in Stage 3 dickite (up to 150 ppm). The Stage 2A ores show enrichment in Ge, which is primarily associated with argyrodite (up to 6.95 wt % Ge) and Ge-bearing enargite (up to 2189 ppm Ge). Co-existing sphalerite has comparatively low Ge content (up to 143 ppm), while Ga (up to 1181 ppm) and In (up to 571 ppm) are higher. Sphalerite in Stage 2B contains up to 611 ppm Ge, 2829 ppm Ga and 2169 ppm In, and locally exhibits fine colloform bands of an uncharacterized Zn-In mineral with compositions close to CuZn 2 (In,Ga)S 4 . Barite, pyrite and galena which occur in association with Stage 2 mineralization were found to play negligible roles as carriers of Ge, Ga and In at Mt Carlton. Analyzed reference samples of enargite from seven similar deposits worldwide have average Ge concentrations ranging from 12 to 717 ppm (maximum 2679 ppm). The deposits from which samples showed high enrichment in critical elements in this study are all hosted in stratigraphic sequences that locally contain carbonaceous sedimentary rocks. In addition to magmatic-hydrothermal processes, such rocks could potentially be important for the concentration of critical elements in high-sulfidation epithermal deposits.

show abstract

Section: Pyritesupporting

confidence: 94%

Mineralogical Distribution of Germanium, Gallium and Indium at the Mt Carlton High-Sulfidation Epithermal Deposit, NE Australia, and Comparison with Similar Deposits Worldwide

et al. 2017

View full text Add to dashboard Cite

show abstract

“…It is important to ore deposits and environmental geochemistry because it hosts economically valuable amounts of Au associated with other metals and metalloids that can be enriched up to the weight percent (wt. %) level, including As, Hg, and Tl (e.g., Arehart et al, 1993;Cook and Chryssoulis, 1990;Chowdhurry et al, 1999;Hofstra and Cline, 2000;Smedley and Kinniburgh, 2002;Goldfarb et al, 2005;Reich et al, 2005;Seedorff et al, 2005;Simmons et al, 2005;Rickard and Luther, 2007;Large et al, 2009;Deditius et al, 2011;Reich et al, 2013). Previous studies have shown that pyrite microstructure is complex and can record valuable information about the chemical and isotopic evolution of the fluids from which it precipitates (e.g., Frimmel, 2005;Wagner and Boyce, 2006;Farquhar et al, 2007;Phillipot et al, 2007;Barker et al, 2009;Deditius et al, 2009a;Reich et al, 2013;Agangi et al, 2014;Ingham et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

“…The pyrite Au-As data form a wedge-shaped zone in compositional space, and the fact that most data points plot below the solid solubility limit defined by Reich et al (2005) indicate that Au 1+ is the dominant form of Au in arsenian pyrite and that Aubearing ore fluids that deposit this sulfide are mostly undersaturated with respect to native Au. The analytical data also show that the solid solubility limit of Au in arsenian pyrite defined by an Au/As ratio of 0.02 is independent of the geochemical environment of pyrite formation and rather depends on the crystal-chemical properties of pyrite and postdepositional alteration.…”

mentioning

confidence: 96%

The coupled geochemistry of Au and As in pyrite from hydrothermal ore deposits

Deditius¹,

Reich²,

Kesler³

et al. 2014

Geochimica et Cosmochimica Acta

Self Cite

438

205

View full text Add to dashboard Cite

The ubiquity of Au-bearing arsenian pyrite in hydrothermal ore deposits suggests that the coupled geochemical behaviour of Au and As in this sulfide occurs under a wide range of physico-chemical conditions. Despite significant advances in the last 20 years, fundamental factors controlling Au and As ratios in pyrite from ore deposits remain poorly known. Here we explore these constraints using new and previously published EMPA, LA-ICP-MS, SIMS, and μ-PIXE analyses of As and Au in pyrite from Carlin-type Au, epithermal Au,

show abstract

“…Although we describe the role of nanoparticles in epithermal ore formation here, perhaps such particles are important in other systems. For example, gold colloids, nanoparticles, and/or nanocrystals also have been documented in "supergene" ± bacterial processes related to weathering of gold ores and gold-nugget formation [19][20][21], in volcanic fumaroles [22,23], in Carlin-type gold deposits [24,25], and also in active geothermal systems [2,[26][27][28]. Finally, metallic sulfide nanoparticles are significant components in the "black smoke" discharging from submarine hydrothermal vents [29][30][31].…”

Section: Introductionmentioning

confidence: 99%

Formation and Aggregation of Gold (Electrum) Nanoparticles in Epithermal Ores

Saunders

Burke

2017

Minerals

View full text Add to dashboard Cite

Here, we review the concept that nanoparticles and colloids may have played a significant role in forming some types of hydrothermal ores deposits, particularly epithermal. This concept was first proposed almost a century ago but the development of new analytical technologies, lab experiments, and the discovery of new epithermal deposits where nanoparticles are evident have added credence to the "gold colloid theory". Nanoparticles are defined to have at least one dimension <10 −7 m, and may have different chemical and physical properties than the bulk solids. Colloids are typically <10 −6 m in diameter and have the added characteristic that they are dispersed in another medium. In epithermal ore-forming solutions, gold or electrum nanoparticles nucleate from supersaturated hydrothermal solutions, and thus this is a "far-from-equilibrium" process. In some cases, gold nanoparticles may simply play a transitory role of aggregating to form much coarser-grained crystals, where all of the evidence of nanoparticles precursor phases is not preserved. However, in some epithermal ores, silica nanoparticles also formed, and their co-deposition with gold (electrum) nanoparticles preserved the gold aggregation features as self-organized "fractal" dendrites. Here, we review existing the data on gold and electrum nanoparticles in epithermal ores, present images of electrum nanoparticles and their aggregates, and discuss the significance of gold nanoparticles formation and aggregation in helping to produce some of the highest-grade gold ores in the world.

show abstract

Solubility of gold in arsenian pyrite

Cited by 778 publications

References 41 publications

Mineralogical Distribution of Germanium, Gallium and Indium at the Mt Carlton High-Sulfidation Epithermal Deposit, NE Australia, and Comparison with Similar Deposits Worldwide

Mineralogical Distribution of Germanium, Gallium and Indium at the Mt Carlton High-Sulfidation Epithermal Deposit, NE Australia, and Comparison with Similar Deposits Worldwide

The coupled geochemistry of Au and As in pyrite from hydrothermal ore deposits

Formation and Aggregation of Gold (Electrum) Nanoparticles in Epithermal Ores

Contact Info

Product

Resources

About