An overview of the platinum-group element nanoparticles in mantle-hosted chromite deposits

Gonzáléz-Jiménez, José María; Reich, Martín

doi:10.1016/j.oregeorev.2016.06.022

Cited by 28 publications

(7 citation statements)

References 103 publications

(116 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is apparently consistent with the fact that over a wide range of temperatures (>500-1000 • C) the Os uptake in pyrite-type structures like laurite takes place by step-growth processes such as dissolution-precipitation instead solid-state diffusion [12,17]. Recently, several authors have reported nanosized PGM sulfide minerals (e.g., cooperite/braggite, laurite), and Pt-Fe alloy, arsenides and oxides by combining focused ion beam and transmission electron microscopy (FIB/TEM) confirming the magmatic origin of these phases [18][19][20]. However, the structure of these intergrowths at the nanoscale remains largely unexplored.This paper provides the first nanoscale characterization of zoned laurites in nature, using a combination of focused ion beam (FIB) micro-sampling techniques, transmission electron microscopy (TEM) and precession electron diffraction (PED) observations.…”

mentioning

confidence: 88%

“…These ultramafic massifs chiefly consist of lherzolite and harzburgite with lesser amounts of dunite and pyroxenites layers, which were locally, intruded by leucocratic dykes at ca. [18][19][20][21][22] A great body of work carried out over the past three decades has provided a deep characterization of the peridotites of the Serranía de Ronda, revealing the existence of four kilometer-scale structural, petrological and geochemical domains from top to bottom of the mantle section ( Figure 1b): (1) garnet-spinel mylonite domain, (2) spinel tectonite domain, (3) granular peridotite domain, and (4) plagioclase tectonite domain [25][26][27][28][29]. These domains represent vestiges of an old Proterozoic (1.8 Ga) subcontinental lithospheric mantle (SCLM) with a protracted record of early exhumation from the roots of thick continental lithosphere and its final emplacement in an extremely attenuated Minerals 2019, 9, 288 4 of 18 shallow continent in the Miocene.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Nanoscale Structure of Zoned Laurites from the Ojén Ultramafic Massif, Southern Spain

et al. 2019

View full text Add to dashboard Cite

We report the first results of a combined focused ion beam and high-resolution transmission electron microscopy (FIB/HRTEM) investigation of zoned laurite (RuS2)-erlichmanite (OS2) in mantle-hosted chromitites. These platinum-group minerals form isolated inclusions (<50 µm across) within larger crystals of unaltered chromite form the Ojén ultramafic massif (southern Spain). High-magnification electron microscopy (HMEM), high angle-annular dark field (HAADF) and precession electron diffraction (PED) data revealed that microscale normal zoning in laurite consisting of Os-poor core and Os-rich rims observed by conventional micro-analytical techniques like field emission scanning electron microscope and electron microprobe analysis (FE-SEM and EPMA) exist at the nanoscale approach in single laurite crystals. At the nanoscale, Os poor cores consist of relatively homogenous pure laurite (RuS2) lacking defects in the crystal lattice, whereas the Os-richer rim consists of homogenous laurite matrix hosting fringes (10–20 nm thickness) of almost pure erlichmanite (OsS2). Core-to-rim microscale zoning in laurite reflects a nonequilibrium during laurite crystal growth, which hampered the intra-crystalline diffusion of Os. The origin of zoning in laurite is related to the formation of the chromitites in the Earth’s upper mantle but fast cooling of the chromite-laurite magmatic system associated to fast exhumation of the rocks would prevent the effective dissolution of Os in the laurite even at high temperatures (~1200 °C), allowing the formation/preservation of nanoscale domains of erlichmanite in laurite. Our observation highlights for the first time the importance of nanoscale studies for a better understanding of the genesis of platinum-group minerals in magmatic ore-forming systems.

show abstract

mentioning

confidence: 88%

mentioning

confidence: 99%

Nanoscale Structure of Zoned Laurites from the Ojén Ultramafic Massif, Southern Spain

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Gold and PGE nanoparticles are increasingly, especially recently, found in ores of different genesis deposits [7,8,[54][55][56]. Although no PGE mineral forms were identified at the Natalkinskoe deposit, the need to continue research in this direction is obvious.…”

Section: Study Of the Chemical Composition Of The Surface Of Arsenopymentioning

confidence: 99%

Platinum Group Elements in Arsenopyrites and Pyrites of the Natalkinskoe Gold Deposit (Northeastern Russia)

et al. 2020

View full text Add to dashboard Cite

The peculiarities of the distribution and binding forms of platinum group elements (Pt, Pd, Ru, Rh, Os and Ir) in the arsenopyrites and pyrites of the Natalkinskoe gold ore deposit (Northeastern Russia) were examined using atomic absorption spectrometry with analytical data selections for single crystals (AAS-ADSSC), a “phase” chemical analysis (PCA) based on AAS of different size-fractions of minerals, scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDX) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The arsenopyrites and pyrites of the Natalkinskoe gold deposit were found to concentrate not only Au but also platinum group elements (PGEs) such as Pt, Pd, Ru and Rh. The PCA showed that the highest contents (in ppm) were found in the monofractions of arsenopyrite—Pt up to 128, Pd up to 20, Ru up to 86 and Rh up to 21—and comparably lower in monofractions of pyrite—Pt to 29, Pd to 15, Ru to 58 and Rh to 5.9. The AAS-ADSSC method revealed two forms of uniformly distributed Pt, Pd and Ru corresponding to the chemically bound element in the structure of the mineral and in the superficial non-autonomous phase (NAP). The superficially bound form dominates over the structural form and presumably exists in a very thin surface layer of the crystal (~100–500 nm). The maximum contents of these PGE, chemically bound in the structure of arsenopyrite, reached values of (in ppm) 48, 5.9 and 48; and in pyrite structure, 68, 5.2 and 34 for Pt, Pd and Ru respectively. The contents of Pt, Pd and Ru related to NAP on the surface of the crystal were significantly higher and amounted (in ppm) for arsenopyrite to 714, 114 and 1083; and for pyrite 890, 62 and 690 for Pt, Pd and Ru, respectively. Preliminary results for the Rh form in arsenopyrite crystals suggest that the surface-related form (154–678 ppm) is more abundant than the structural form (17–45 ppm). Data from studying the surfaces of sulphide minerals by SEM-EDX and LA-ICP-MS confirmed the presence of Pt, Pd, Ru and Rh on the surface of arsenopyrite and pyrite crystals. These methods generated primary data on the content of Os and Ir in arsenopyrite and pyrite in the surface layer. The maximum content of Os and Ir found in arsenopyrites was up to 0.7 wt%. PGE-enriched fluids (up to ~3 ppm Pt) may exist in the gold ore deposit. It is assumed that there is a common mechanism of impurities uptake associated with the active role of the crystal surface and surface defects for gold-bearing arsenopyrites and pyrites. The surface enrichment is due to peculiarities in the crystal growth mechanism through the medium of NAP and the dualism of the element distribution coefficient in the system of mineral–hydrothermal solution, which is higher for NAP, compared to the volume of the crystal. Although mineral forms of Pt, Pd, Ru, Rh, Os and Ir have not been found at the Natalkinskoe gold deposit, their existence in the form of nano-scale particles is not excluded. This follows from the evolutionary model of surficial NAPs, assuming their partial transformation and aggregation with the formation of nano- and micro-sized autonomous phases of trace elements. The presence of PGE in the ores and the possibility of their extraction significantly increase the quality and value of the extracted raw gold materials at the Natalkinskoe deposit, and adds to the list of known platiniferous ore formations.

show abstract

“…This problem is thus categorized as ill-posed. To address this issue, we formulated the ND method as the following optimization problem: 34 J ¼ ky À Gxk 2 + lkLxk 2 (5) subject to x $ 0.…”

Section: Non-negative Deconvolutionmentioning

confidence: 99%

“…1,2 Metal nanoparticles may be toxic to living cells if they are overloaded, and hence, determination of their distributions and transport mechanisms is crucial for biological and medical applications. 3 Nano-to micrometre particles are also present in natural inorganic materials and can provide clues to understanding the condensation mechanisms of particular elements such as precious metals in ore formations, 4,5 the effects of nanoscale mineral particles on the environment, 6 and the origin of pre-solar grains in meteorites. 7,8 Several methods enable simultaneous investigation of the spatial distribution and elemental concentration of nano-to micro-sized particles.…”

Section: Introductionmentioning

confidence: 99%

A numerical inversion method for improving the spatial resolution of elemental imaging by laser ablation-inductively coupled plasma-mass spectrometry

Aonishi

Hirata

Kuwatani

et al. 2018

J. Anal. At. Spectrom.

View full text Add to dashboard Cite

show abstract

An overview of the platinum-group element nanoparticles in mantle-hosted chromite deposits

Cited by 28 publications

References 103 publications

Nanoscale Structure of Zoned Laurites from the Ojén Ultramafic Massif, Southern Spain

Nanoscale Structure of Zoned Laurites from the Ojén Ultramafic Massif, Southern Spain

Platinum Group Elements in Arsenopyrites and Pyrites of the Natalkinskoe Gold Deposit (Northeastern Russia)

A numerical inversion method for improving the spatial resolution of elemental imaging by laser ablation-inductively coupled plasma-mass spectrometry

Contact Info

Product

Resources

About