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 …

Arsenian pyrite is the major host mineral of gold in Carlin type gold deposit (CTGD) and forms during the interaction of H 2 S bearing hydrothermal fluids with Fe …

A significant characteristic distinguishing Carlin-type Au deposits from other Au deposits is the abundance of invisible Au in arsenian pyrite. Gold occurs primarily as ionic Au 1+ in arsenian pyrite and is unstable during subsequent thermal events. In this study, we used the focused ion beam combined with scanning electron microscope (FIB …

Pyrite is the most common sulfide in the Earth. In the presence of arsenopyrite its oxidation is delayed, and instead, the arsenopyrite increases its oxidation rate, releasing As (III) …

Overgrowths of arsenian pyrite layers (up to 3.2 wt. % As and/or up to 1.1 wt. % Mn) onto As-free pyrite indicate fluctuation in As content of the hydrothermal fluid. Mercury, in the form of cinnabar, occurs in up to 5 μm grains within arsenian pyrite layers, usually forming distinct cinnabar-enriched micro-layers.

Arsenian Pyrite mineral data, information about Arsenian Pyrite, its properties and worldwide locations.

Arsenic-rich (arsenian) pyrite can contain up to tens of thousands of parts per million (ppm) of toxic heavy metals such as Hg, Tl, and Cd, although few data are available on their solid solubility behavior.

The arsenian pyrite was shown to exist as As 0.026 FeS 1.974 (COD 9013070) and As 0.54 FeS 1.46 (COD 9013071). Arsenian pyrite was detected after one week of biostimulation, with 54% of the monitoring wells located near and downgradient of the injection wells showing evidence of arsenian pyrite formation.

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 …

The obtained spectroscopic and fluid-mineral partitioning data were interpreted using quantum chemistry and thermodynamic approaches to generate a new structural and physico-chemical model that reveals the fundamental role played by arsenic in gold incorporation in pyrite and Fe sulfarsenides. Atomic State of Gold from Spectroscopic Data

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 …

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 …

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.

An arsenic-bearing variety of pyrite that may contain up to about 10 at.% of As (Abraitis et al., 2004). Not uncommon; often zoned. Arsenic may be present in different valence …

XANES measurements on gold-bearing arsenian pyrite from the Twin Creeks Carlin-type gold deposits show that gold is present as both Au {sup 0} and Au {sup 1+} and arsenic is present as As {sup...

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 …

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 ...

Arsenian pyrite is the most important and in many cases the only Au-bearing mineral in Carlin-type and some epithermal deposits. …

Abstract. 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 …

The initial pyrite cores, which acted as substrates for the arsenian pyrite gold host, were sourced from a barren fluid related to either sedimentary or magmatic-hydrothermal processes. Trace elements from EPMA and APT suggest that this arsenic-rich, gold-bearing fluid was saline and contained appreciable amounts of potassium.

In arsenian pyrites with Au/As Ͻ 0.02, native Au nanoparticles were not observed by HRTEM, and all of the Au measured is inferred to be structurally bound in solid solution. The microanalytical results, coupled …

Abstract. 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 …

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 arsenian pyrite, As 1--pyrite, in which As 1-substitutes for S [Fe(As,S) 2].As 3+-pyrite has been observed as colloformic overgrowths on As-free pyrite in a hydrothermal gold deposit at Yanacocha, …

Abstract 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:g (344 E cm−1), Ag (379 cm−1), and Tg(3) (432 cm−1).

The scenario of metastable crystallisation of arsenian pyrite (C) proposes formation of the mineral by fast growth from oversaturated fluids with As content controlled by surface adsorption and...

Pyrite with As above 1 wt% and called arsenian pyrite is an essential phase in ore deposits and sedimentary rocks. Assemblages of arsenopyrite with pyrite …

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 …

Low-As pyrite coexisting with arsenopyrite is a product of disequilibrium crystallisation; (B) a scenario of control of As content in pyrite coexisting with arsenopyrite by thermodynamic parameters including temperature, pressure, the activity of components and fluid composition and (C) a scenario where arsenian pyrite is a metastable mineral.

arsenian pyrite compositions plotting below the limit contain Au 1. On the basis of these observations, the upper bound is interpreted to represent a solubility limit for solid solution of Au as a function of As in arsenian pyrite between 150°C and 250°C, the approximate conditions under which samples used in the study were deposited. ...

ABSTRACT XANES measurements on gold-bearing arsenian pyrite from the Twin Creeks Carlin-type golddeposits show that gold is present as both Au0 and AuI+ and arsenic is present at AsI–. Au0 is attributedto sub-micrometer size inclusions of free gold, whereas AuI+ is attributed to gold in the lattice of thearsenian pyrite.