The solid solubility limits of Hg in arsenian pyrite—i.e., the upper limit of the wedge-shaped zone in compositional space—are similar to the one previously defined for Au by Reich et al. (2005) (C Hg,Au = 0.02C As + 4 × 10 −5), whereas the solubility limit of Tl in arsenian pyrite is approximated by a ratio of Tl/As = 1. In contrast ...

A Raman spectroscopic study on the nature of As-S substitution in natural arsenian pyrite [Fe(S,As) 2] is presented, covering a compositional range of 0.01–4.6 at% As.Three Raman-active modes were identified in the Raman spectrum of a nearly pure pyrite: E g (344 cm −1), A g (379 cm −1), and T g (3) (432 cm −1).The Raman …

The arsenian pyrite does not always exhibit high Au values (e.g., Fleet et al., 1993) because it is apparent that the As-rich fluids are not invariably gold-bearing. Moreover, the reason why the Au content in host rock pyrite is low could be attributed to a low water/rock (W/R) ratio, compared to the high W/R ratio in fertile veins. ...

The results show that there are two populations of native gold in arsenian pyrite. One is comprised of sub-μm size gold particles (0.1 to 0.2 μm) that are occasionally present in the gold-bearing arsenian pyrite disseminated in the host rocks. This arsenian pyrite is interpreted to have been formed by sulfidation of ferroan calcite and ...

Arsenian pyrite in the Shuiyindong Carlin-type gold deposit in Guizhou, China, is the major host for gold with 300 to 4,000 ppm Au and 0.65 to 14.1 wt.% As. Electron miroprobe data show a negative …

Gold, arsenic, and copper zoning in pyrite: A record of fluid chemistry and growth kinetics ... As, and Cu and atomic-scale transitions from homogeneous to heterogeneous "island" arsenian pyrite formed as a consequence of heteroepitaxial Stranski-Krastanov growth. Nanoscale Au oscillatory zoning is interpreted as a …

Arsenian pyrite is confirmed as the most important gold-hosting mineral and four types of gold-bearing arsenian pyrite are recognized. Among these four types, the lowest amount of gold and arsenic (<1 wt % As; 17-60 ppm Au) is contained in arsenian pyrite with relatively large grain sizes (10-30 mu m). It formed at relatively high temperatures ...

Active, shallow-water (2–10 m below sea level) and low temperature (up to 115 °C) hydrothermal venting at Paleochori Bay, nearshore Milos Island, Greece, discharges CO2 and H2S rich vapors (e.g., low-Cl fluid) and high-salinity liquids, which leads to a diverse assemblage of sulfide and alteration phases in an area of …

The solubility of Au in nonarsenian (pure) pyrite is very low (a few ppm), and values greater than 100 ppm are usually associated with As-rich compositions (Cook and Chryssoulis, 1990). Whereas Tauson 1998, Tauson 1999, Tauson et al 1998 obtained a solubility of 3 ± 1 ppm Au in pyrite at 500°C and 1 kbar, numerous investigators have …

The structural chemistry of gold in arsenian pyrite (FeS 2) and arsenopyrite (FeAsS) is as yet unknown, despite the economic importance of this element and its potential recovery from low-grade ores and mine tailings.The systematic co-occurrence of Au and As poses a challenge for measuring the Au L 3-edge X-ray absorption spectra because the Au Lα …

Arsenian pyrite is known to have a strong association with gold in most auriferous refractory deposits, and thus understanding the chemical speciation of arsenic in localized environments in arsenian pyrite provides an important basis for determining its reactivity and mobility. However, arsenic is fast-oxidizing among elements in the Fe-As-S system …

Arsenian pyrite is known to have a strong association with gold in most auriferous refractory deposits, and thus understanding the chemical speciation of arsenic in localized environments in arsenian pyrite provides an important basis for determining its reactivity and mobility. However, arsenic is fast-oxidizing among elements in the Fe-As-S ...

The mineral pyrite, or iron pyrite, also known as fool's gold, is an iron sulfide with the formula FeS 2. This mineral's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence …

Pyrite. Abstract. Pyrite is the most common sulfide in the Earth. In the presence of arsenopyrite its oxidation is delayed, and instead, the …

In Carlin-type deposits, where arsenian pyrite has been studied most intensively, a compilation of previously published Au-As SIMS and EMPA analyses (Fig. 1) shows that almost all data points fall within a wedge-shaped zone in log (Au)–log (As) space, which is limited by a relatively sharp boundary.Although available information on …

Pyrite with As content above about 1 wt% As is called arsenian pyrite (Stepanov et al. 2021; Wells and Mullens 1973) and has been found to concentrate …

The results indicate that the arsenian pyrite rim is composed of numerous nanoparticulate pyrite grains (rather than a single crystal), and gold nanoparticles (Au0) occur mainly in sub-rim with the highest Au content, which are porous and have lower degrees of order. We propose that nanoparticulate arsenian pyrite attachment and …

Micron-scale patchy distribution of Au, As, and Cu and atomic-scale transitions from homogeneous to heterogeneous "island" arsenian pyrite formed as a …

The gold nanoparticles are dispersed throughout arsenian pyrite rims (1-10 mm thick, up to 10 wt% As), which have overgrown diagenetic As-poor pyrite. The gold nanoparticles are concentrated throughout arsenic-rich pyrite (up to 1 vol% Au, equivalent to 3 wt% Au estimated from HAADF-STEM images), but are not observed in associated …

The average tenor of the pyrite, if all the gold were in the pyrite, would be 0.10 percent at Cortez and 0.14 percent at Carlin. These calculated values are similar to the analytical values. The calculated tenor of the carbonaceous material, however-if such material were considered to be the mineral host of the gold-would be 0.28 percent at ...

Arsenian pyrite is an abundant mineral occurring in many geological settings at the Earth's surface, including hydrothermal ore deposits which are the main source of Au. So-called "invisible" (or refractory) form of Au is present in pyrites in all types of these deposits, and its concentration is often directly correlated with As content. ...

This report describes a new form of arsenian pyrite, called As 3+-pyrite, in which As substitutes for Fe [(Fe,As)S 2], in contrast to the more common form of …

Invisible gold in natural and synthetic arsenian pyrite and marcasite correlates with anomalous As content and Fe deficiency, and high contents of invisible gold in most natural and all synthetic arsenopyrite correlate with excess As and Fe deficiency. As-rich, Fe-de-ficient arsenopyrite synthesized hydrothermally contains up to 3.0 wt% Au ...

Arsenian pyrite is confirmed as the most important gold-hosting mineral and four types of gold-bearing arsenian pyrite are recognized. Among these four types, the lowest amt. of gold and arsenic (<1 wt % As; 17-60 ppm Au) is contained in arsenian pyrite with relatively large grain sizes (10-30 μm). It formed at relatively high temps.

Ore minerals are dominated by pyrite and arsenian pyrite, with lesser amounts of chalcopyrite, galena, sphalerite, and locally arsenopyrite. Other ore minerals include marcasite, native gold, electrum, and silver sulfosalts. Chalcocite, covellite, digenite, and different iron and manganese oxides have been identified in the oxidized zone. ...

Enrichment of As and Au at the overgrowth rims of arsenian pyrite is a distinctive feature of Carlin-type gold ores. Revealing distribution of such key elements in high resolution is of fundamental importance yet often proves challenging. In this study, repeated non-oxidative acid etching of ore samples from Shuiyindong gold deposit was …

Arsenian pyrite is known to have a strong association with gold in most auriferous refractory de-posits, and thus understanding the chemical speciation of arsenic in localized environments in arsenian pyrite provides an important basis for determining its reactivity and mobility. However, arsenic is fast-

XANES measurements on gold-bearing arsenian pyrite from the Twin Creeks Carlin-type gold deposits show that gold is present as both Au 0 and Au (super I+) and arsenic is present at As (super I-) . Au 0 is attributed to sub-micrometer size inclusions of free gold, whereas Au (super I+) is attributed to gold in the lattice of the arsenian …

A ternary plot of the arsenian pyrite Fe-S-As (at %) can prove whether As replaces S or Fe [49,53], a trend line parallel to the As-S contents distribution as defined in the Fe-S-As (at%) ternary ...

A new mode of arsenic incorporation into arsenian pyrite has been discovered. Electron microprobe analyses and elemental maps of arsenian pyrite from Pueblo Viejo, Dominican Republic, show that its chemical composition varies from (Fe 0.998 As 0.003) 1.001 S 2 to (Fe 0.963 As 0.050 Cu 0.003 Ag 0.001) 1.017 S 2 and that …