Special Issue "Advances in Economic Minerals"

Quicklinks

A special issue of Minerals (ISSN 2075-163X).

Deadline for manuscript submissions: closed (31 August 2012)

Special Issue Editor

Guest Editor
Prof. Dr. Michael Meyer

Institute of Mineralogy and Economic Geology, RWTH Aachen University, Wüllnerstrasse 2, 52056 Aachen, Germany
Website | E-Mail
Phone: +492418095774
Fax: +49 241 80 92153
Interests: economic geology; geometallurgy of high-tech metals; mineralogy and geochemistry of hydrothermal systems; ore petrology

Special Issue Information

Dear Colleagues,

Recent concern about available resources for rare and scarce commodities has led to the concept of criticality of ore minerals and associated metals. The two central dimensions of criticality are importance in use and availability. Critical minerals and metals (e.g., Sb, In, Be, Nb, PGM, Ga, REE, Ge, Ta, etc) are thus defined by the risks for supply shortage and their impacts on emerging technologies. Availability reflects firstly considerations on distribution and abundance of critical minerals and secondly knowledge of efficient extraction and processing methods. The purpose of this special issue “Advances in Economic Minerals” is to publish recent research that focuses on sulphide and oxide ore mineralogy and mineral chemistry as well as mineral technology. The special issue will highlight recent advances in both fundamental and applied studies across a wide range of areas involved in the formation of ore-grade concentrations of critical minerals, as well as the application of mineralogical and geochemical methods to exploration, ore dressing, and waste management.

Prof. Dr. Michael Meyer
Guest Editor

Keywords

  • ore mineralogy
  • mineral chemistry
  • high-tech metals
  • geometallurgy
  • ore deposits

Published Papers (11 papers)

View options order results:
result details:
Displaying articles 1-11
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle Mineralogy and Trace Element Chemistry of Ferberite/Reinite from Tungsten Deposits in Central Rwanda
Minerals 2013, 3(2), 121-144; doi:10.3390/min3020121
Received: 7 January 2013 / Revised: 7 March 2013 / Accepted: 7 March 2013 / Published: 2 April 2013
Cited by 5 | PDF Full-text (3974 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Tungsten mineralization in hydrothermal quartz veins from the Nyakabingo,Gifurwe and Bugarama deposits in central Rwanda occurs as the iron-rich endmember ofthe wolframite solid solution series (ferberite) and in the particular form of reinite, whichrepresents a pseudomorph of ferberite after scheelite. Primary ferberite, reinite
[...] Read more.
Tungsten mineralization in hydrothermal quartz veins from the Nyakabingo,Gifurwe and Bugarama deposits in central Rwanda occurs as the iron-rich endmember ofthe wolframite solid solution series (ferberite) and in the particular form of reinite, whichrepresents a pseudomorph of ferberite after scheelite. Primary ferberite, reinite and latesecondary ferberite are characterized by their trace element chemistry and rare earthelement patterns. The replacement of scheelite by ferberite is also documented in the traceelement composition. Primary ferberite shows high Mg, Zn, Sc, V, Nb, In and Snconcentrations, but very low Ca, Pb, Sr and Ba contents. Reinite and late secondaryferberite display an uncommon trace element composition containing high concentrationsof Ca, Pb, Sr, Ba, As and Ga, but very low levels in Sn, Zr, Hf, In, Ti, Sc, Nb, Ta, Mg andZn. Late secondary ferberite replacing primary ferberite is characterized by additionalenrichments in Bi, Pb, As and Sb. The rare earth element patterns of reinite and secondaryferberite are also similar to hydrothermal scheelite. The formation of the tungsten depositsin central Rwanda is interpreted to be epigenetic in origin, and the hydrothermalmineralizing fluids are related to the intrusion of the G4-granites. Full article
(This article belongs to the Special Issue Advances in Economic Minerals)
Open AccessArticle Three Compositional Varieties of Rare-Earth Element Ore: Eudialyte-Group Minerals from the Norra Kärr Alkaline Complex, Southern Sweden
Minerals 2013, 3(1), 94-120; doi:10.3390/min3010094
Received: 8 December 2012 / Revised: 18 January 2013 / Accepted: 25 February 2013 / Published: 20 March 2013
Cited by 8 | PDF Full-text (2845 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Agpaitic nepheline syenites at the Norra Kärr Alkaline Complex, southern Sweden, are rich in zirconium and rare-earth elements (REE), which are mainly accommodated in eudialyte-group minerals (EGM). Norra Kärr hosts three compositionally distinct groups of EGM, which are complex zirconosilicates. Analyses of EGM
[...] Read more.
Agpaitic nepheline syenites at the Norra Kärr Alkaline Complex, southern Sweden, are rich in zirconium and rare-earth elements (REE), which are mainly accommodated in eudialyte-group minerals (EGM). Norra Kärr hosts three compositionally distinct groups of EGM, which are complex zirconosilicates. Analyses of EGM by electron beam energy-dispersive (SEM-EDS) and wavelength-dispersive (WDS-EMP) X-ray microanalysis are presented and compared, complemented by whole-rock analyses. The SEM-EDS and WDS-EMP methods produce comparable results for most elements. Considering that most SEM instruments have a user-friendly EDS system, it is a useful tool for reconnaissance work in research and especially in exploration-related studies. The EGM evolved markedly from an initial Fe-rich and REE-poor, but HREE-dominated variety, to an intermediate Fe-Mn and HREE-rich one, and to a final Mn- and LREE-rich variety, which occur in rocks classified as lakarpite and grennaite. Based on the Mn/(Fe+Mn) ratios of the EGM, this trend is interpreted as a result of magmatic evolution. The threefold diversity of EGM presented in this work is much broader than has previously been documented. Full article
(This article belongs to the Special Issue Advances in Economic Minerals)
Open AccessArticle High and Low Temperature Gold Mineralizations in the Fe–Cu–Zn Sulfide Deposits of Corchia Ophiolite, Northern Italian Apennine
Minerals 2013, 3(1), 82-93; doi:10.3390/min3010082
Received: 7 September 2012 / Revised: 19 February 2013 / Accepted: 25 February 2013 / Published: 5 March 2013
PDF Full-text (2804 KB) | HTML Full-text | XML Full-text
Abstract
Gold has been found in the Cyprus-type volcanogenic massive sulfide ore (VMS) deposits of Corchia ophiolite (Parma province, Italy) in the Cantiere Donnini, Speranza and Pozzo mining sites. At Cantiere Donnini and Speranza, the mineralization occurs at the contact between pillow lava and
[...] Read more.
Gold has been found in the Cyprus-type volcanogenic massive sulfide ore (VMS) deposits of Corchia ophiolite (Parma province, Italy) in the Cantiere Donnini, Speranza and Pozzo mining sites. At Cantiere Donnini and Speranza, the mineralization occurs at the contact between pillow lava and sedimentary rocks. The Pozzo mineralization is hosted by a serpentinite. Concentrations of gold up to 3070 ppb have been reported for the Cantiere Donnini and up to 6295 ppb in the Pozzo mine. According to the field relationships, gold composition, mineralogical assemblage and sulfur isotope data, we can conclude that two different types of gold mineralization have been recognized in the Corchia ophiolite: (1) formed at low temperature in submarine environment (Cantiere Donnini and Speranza) and (2) formed at high temperature in the oceanic mantle (Pozzo) by segregation of an immiscible sulfide liquid. Full article
(This article belongs to the Special Issue Advances in Economic Minerals)
Open AccessArticle Water- and Boron-Rich Melt Inclusions in Quartz from the Malkhan Pegmatite, Transbaikalia, Russia
Minerals 2012, 2(4), 435-458; doi:10.3390/min2040435
Received: 16 August 2012 / Revised: 24 October 2012 / Accepted: 25 October 2012 / Published: 15 November 2012
Cited by 7 | PDF Full-text (926 KB) | HTML Full-text | XML Full-text
Abstract
In this paper we show that the pegmatite-forming processes responsible for the formation of the Malkhan pegmatites started at magmatic temperatures around 720 °C. The primary melts or supercritical fluids were very water- and boron-rich (maximum values of about 10% (g/g) B2
[...] Read more.
In this paper we show that the pegmatite-forming processes responsible for the formation of the Malkhan pegmatites started at magmatic temperatures around 720 °C. The primary melts or supercritical fluids were very water- and boron-rich (maximum values of about 10% (g/g) B2O3) and over the temperature interval from 720 to 600 °C formed a pseudobinary solvus, indicated by the coexistence of two types of primary melt inclusions (type-A and type-B) representing a pair of conjugate melts. Due to the high water and boron concentration the pegmatite-forming melts are metastable and can be characterized either as genuine melts or silicate-rich fluids. This statement is underscored by Raman spectroscopic studies. This study suggested that the gel state proposed by some authors cannot represent the main stage of the pegmatite-forming processes in the Malkhan pegmatites, and probably in all others. However there are points in the evolution of the pegmatites where the gel- or gel-like state has left traces in form of real gel inclusions in some mineral in the Malkhan pegmatite, however only in a late, fluid dominated stage. Full article
(This article belongs to the Special Issue Advances in Economic Minerals)
Open AccessArticle Indium-Carrier Minerals in Polymetallic Sulphide Ore Deposits: A Crystal Chemical Insight into an Indium Binding State Supported by X-ray Absorption Spectroscopy Data
Minerals 2012, 2(4), 426-434; doi:10.3390/min2040426
Received: 28 August 2012 / Revised: 17 October 2012 / Accepted: 18 October 2012 / Published: 6 November 2012
PDF Full-text (422 KB) | HTML Full-text | XML Full-text
Abstract
Indium is a typical chalcophile element of the Earth’s crust, with a very low average content that seldom forms specific minerals, occurring mainly as dispersed in polymetallic sulphides. Indium recovery is based primarily on zinc extraction from sphalerite, the prototype of so-called tetrahedral
[...] Read more.
Indium is a typical chalcophile element of the Earth’s crust, with a very low average content that seldom forms specific minerals, occurring mainly as dispersed in polymetallic sulphides. Indium recovery is based primarily on zinc extraction from sphalerite, the prototype of so-called tetrahedral sulphides, wherein metal ions fill half of the available tetrahedral sites within the cubic closest packing of sulphur anions, leaving interstices accessible for further in-filling. Ascertaining the tendency towards the establishment of In-In interactions through an x-ray absorption spectroscopy approach would efficiently contribute to understanding the behavior of indium in the carrier mineral. The successful results of applying such a near-edge absorption (XANES) study at In L3-edge to samples collected at the Lagoa Salgada polymetallic orebody in the Iberian Pyrite Belt (IPB) are described and the crystal chemistry of indium is re-evaluated, disclosing a potential clue for the metal binding state in polymetallic sulphides. Full article
(This article belongs to the Special Issue Advances in Economic Minerals)
Figures

Open AccessArticle Geology and Age Constraints on the Origin of the Intrusion-Related, Sheeted Vein-Type Åkerberg Gold Deposit, Skellefte District, Sweden
Minerals 2012, 2(4), 385-416; doi:10.3390/min2040385
Received: 11 September 2012 / Revised: 21 October 2012 / Accepted: 23 October 2012 / Published: 31 October 2012
PDF Full-text (1430 KB) | HTML Full-text | XML Full-text
Abstract
The Early Proterozoic (~1.9 Ga) Skellefte mining district in northern Sweden hosts abundant base metal deposits, but there are also gold-only deposits. The Åkerberg gold ore is unusual given the noted lack of alteration, a scarcity of sulfides and gold associated with thin
[...] Read more.
The Early Proterozoic (~1.9 Ga) Skellefte mining district in northern Sweden hosts abundant base metal deposits, but there are also gold-only deposits. The Åkerberg gold ore is unusual given the noted lack of alteration, a scarcity of sulfides and gold associated with thin (mm-cm wide) parallel quartz veins hosted in a gabbro. The gold content is positively correlated with the density of quartz veins, but gold often occurs between veins and also in parts of the gabbro where there is no veining. The gabbro is intruded by a granodiorite and associated pegmatite bodies, and U-Pb dating of zircon and baddeleyite suggest that these lithologies developed close in time at around 1.88 Ga ago. There are no primary inclusions in quartz veins, but different types of secondary aqueous inclusions occur. The Åkerberg ore is interpreted as a sheeted vein complex, with veins constrained to tensional cracks induced when a granodioritic magma intruded the competent, sheet-like gabbro intrusion. It is suggested that unmixing of the felsic magma also produced pegmatite bodies and a gel-like melt which invaded fractures in the gabbro and deposited silica. In a comparison, the Åkerberg ore shares many characteristics with the intrusion-related style of gold mineralizations. Full article
(This article belongs to the Special Issue Advances in Economic Minerals)
Open AccessArticle Platinum-Group Minerals in Chromitites of the Niquelândia Layered Intrusion (Central Goias, Brazil): Their Magmatic Origin and Low-Temperature Reworking during Serpentinization and Lateritic Weathering
Minerals 2012, 2(4), 365-384; doi:10.3390/min2040365
Received: 3 September 2012 / Revised: 19 October 2012 / Accepted: 19 October 2012 / Published: 30 October 2012
Cited by 9 | PDF Full-text (1603 KB) | HTML Full-text | XML Full-text
Abstract
A variety of platinum-group-minerals (PGM) have been found to occur associated with the chromitite and dunite layers in the Niquelândia igneous complex. Two genetically distinct populations of PGM have been identified corresponding to phases crystallized at high temperatures (primary), and others formed or
[...] Read more.
A variety of platinum-group-minerals (PGM) have been found to occur associated with the chromitite and dunite layers in the Niquelândia igneous complex. Two genetically distinct populations of PGM have been identified corresponding to phases crystallized at high temperatures (primary), and others formed or modified during post-magmatic serpentinization and lateritic weathering (secondary). Primary PGM have been found in moderately serpentinized chromitite and dunite, usually included in fresh chromite grains or partially oxidized interstitial sulfides. Due to topographically controlled lateritic weathering, the silicate rocks are totally transformed to a smectite-kaolinite-garnierite-amorphous silica assemblage, while the chromite is changed into a massive aggregate of a spinel phase having low-Mg and a low Fe3+/Fe2+ ratio, intimately associated with Ti-minerals, amorphous Fe-hydroxides, goethite, hematite and magnetite. The PGM in part survive alteration, and in part are corroded as a result of deep chemical weathering. Laurite is altered to Ru-oxides or re-crystallizes together with secondary Mg-ilmenite. Other PGM, especially the Pt-Fe alloys, re-precipitate within the altered chromite together with kaolinite and Fe-hydroxides. Textural evidence suggests that re-deposition of secondary PGM took place during chromite alteration, controlled by variation of the redox conditions on a microscopic scale. Full article
(This article belongs to the Special Issue Advances in Economic Minerals)
Open AccessArticle Major- and Trace-Element Compositions of Indicator Minerals that Occur as Macro- and Megacrysts, and of Xenoliths, from Kimberlites in Northeastern Angola
Minerals 2012, 2(4), 318-337; doi:10.3390/min2040318
Received: 30 August 2012 / Revised: 22 September 2012 / Accepted: 28 September 2012 / Published: 26 October 2012
Cited by 2 | PDF Full-text (2579 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In this study, we compare the major- and trace-element compositions of olivine, garnet, and clinopyroxene that occur as single crystals (142 grains), with those derived from xenoliths (51 samples) from six kimberlites in the Lucapa area, northeastern Angola: Tchiuzo, Anomaly 116, Catoca, Alto
[...] Read more.
In this study, we compare the major- and trace-element compositions of olivine, garnet, and clinopyroxene that occur as single crystals (142 grains), with those derived from xenoliths (51 samples) from six kimberlites in the Lucapa area, northeastern Angola: Tchiuzo, Anomaly 116, Catoca, Alto Cuilo-4, Alto Cuilo-63 and Cucumbi-79. The samples were analyzed using electron probe microanalysis (EPMA) and laser-ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS). The results suggest different paragenetic associations for these kimberlites in the Lucapa area. Compositional overlap in some of the macrocryst and mantle xenolith samples indicates a xenocrystic origin for some of those macrocrysts. The presence of mantle xenocrysts suggests the possibility of finding diamond. Geothermobarometric calculations were carried out using EPMA data from xenoliths by applying the program PTEXL.XLT. Additional well calibrated single-clinopyroxene thermobarometric calculations were also applied. Results indicate the underlying mantle experienced different equilibration conditions. Subsequent metasomatic enrichment events also support a hypothesis of different sources for the kimberlites. These findings contribute to a better understanding of the petrogenetic evolution of the kimberlites in northeastern Angola and have important implications for diamond exploration. Full article
(This article belongs to the Special Issue Advances in Economic Minerals)

Review

Jump to: Research

Open AccessReview Towards a Model for Albitite-Type Uranium
Minerals 2013, 3(1), 36-48; doi:10.3390/min3010036
Received: 22 August 2012 / Revised: 21 December 2012 / Accepted: 4 January 2013 / Published: 17 January 2013
Cited by 4 | PDF Full-text (1690 KB) | HTML Full-text | XML Full-text
Abstract
Albitite-type uranium deposits are widely distributed, usually of low grade (<1% U3O8), but are often large and collectively contain over 1 million tonnes of U3O8. Uranium is hosted in a wide range of metamorphic lithologies,
[...] Read more.
Albitite-type uranium deposits are widely distributed, usually of low grade (<1% U3O8), but are often large and collectively contain over 1 million tonnes of U3O8. Uranium is hosted in a wide range of metamorphic lithologies, whose only common characteristic is that they have been extensively mylonitised. Ore minerals are disseminated and rarely in megascopic veins, within and adjacent to albitised mylonites. Grain size is uniformly fine, generally less than 50 microns. Scanning electron microscopy reveals that spatial association between uranium and various Ti-bearing phases is common. Gangue minerals include albite, carbonates (calcite and dolomite), and sodic pyroxene and amphibole. The ore rarely contains economic metals apart from uranium, phosphorous at Itataia being an exception. There is widespread evidence of hydrothermal zirconium mobility and hydrothermal zircon and other Zr phases are frequent and in some cases abundant gangue minerals. Positive correlations are noted between uranium and various high field strength elements. The group remains poorly described and understood, but a link to iron-oxide copper-gold (IOCG) deposits and/or carbonatite and/or alkaline magmatism is plausible. Full article
(This article belongs to the Special Issue Advances in Economic Minerals)
Open AccessReview Geological, Mineralogical and Geochemical Aspects for Critical and Rare Metals in Greece
Minerals 2012, 2(4), 300-317; doi:10.3390/min2040300
Received: 4 September 2012 / Revised: 9 October 2012 / Accepted: 10 October 2012 / Published: 19 October 2012
Cited by 4 | PDF Full-text (900 KB) | HTML Full-text | XML Full-text
Abstract
The European Union (EU) is highly dependent on critical and rare metals which are very important for a sustainable development. However, European industry is not able to cover its demands from native sources and it imports commodities from third countries. Greece is one
[...] Read more.
The European Union (EU) is highly dependent on critical and rare metals which are very important for a sustainable development. However, European industry is not able to cover its demands from native sources and it imports commodities from third countries. Greece is one of the EU countries with the most potential for supplying these strategic metallic raw materials in the future, since it hosts a large number of ore deposits. The epithermal- and porphyry-type deposits and the reduced intrusion related systems of the Serbomacedonian and the Rhodope metallogenic provinces in Northeastern Greece are promising targets for a future exploitation and exploration in Sb, Te, Mo, Re, Ga, In, REE and PGE. Greece is the leading producer of Ni and Al in the EU from laterites and bauxites of central and northern Greece. These deposits also contain significant amounts of Co or REE which should be considered in the future plans of the processing industries. REE are found in high contents at the placer deposits between Chalkidiki and Kavala (North Greece) and elevated PGE concentrations are associated with the chromitites of northwestern Greece. Therefore, the mineral wealth of Greece can contribute significantly to a sustainable and a competitive economy of Europe. Full article
(This article belongs to the Special Issue Advances in Economic Minerals)
Open AccessReview Textural Evidence of Episodic Introduction of Metallic Nanoparticles into Bonanza Epithermal Ores
Minerals 2012, 2(3), 228-243; doi:10.3390/min2030228
Received: 28 June 2012 / Revised: 27 July 2012 / Accepted: 3 August 2012 / Published: 14 August 2012
Cited by 8 | PDF Full-text (993 KB) | HTML Full-text | XML Full-text
Abstract
Tertiary low sulfidation (LS) epithermal deposits in the western USA often show evidence of the former presence of nanoparticle-sized precious-metal and silica phases in the highest grade (bonanza) ores. Here, nanoparticles are defined to have a size less than ~107 m.
[...] Read more.
Tertiary low sulfidation (LS) epithermal deposits in the western USA often show evidence of the former presence of nanoparticle-sized precious-metal and silica phases in the highest grade (bonanza) ores. Here, nanoparticles are defined to have a size less than ~107 m. The ore-mineral textures that formed from aggregation of nanoparticles (or colloids) observed to date in these ores include electrum and naumannite (Ag2Se). Here it is proposed that chalcopyrite also forms nanoparticles in these ores, but sulfide nanoparticles apparently have significantly different physical (surface) properties than the precious-metal phases, and thus exhibit different mineral textures (e.g., no textural evidence of previous chalcopyrite nanoparticles). Textures described here show that nanoparticles of precious-metal phases and silica were episodically and often repeatedly deposited to form the banded bonanza veins typical of many western USA epithermal deposits. Chalcopyrite is the most abundant metal-sulfide mineral in these bonanza ores, and it was also deposited episodically as well, and it appears to replace earlier formed naumannite dendrites. However, this apparent “replacement” texture may just be the result of naumannite dendrite limbs trapping chalcopyrite nanoparticles that later recrystallized to the apparent replacement texture. The episodic and repetitive nature of the metal-depositing events may record periodic “degassing” of magma chambers at depth, where metals are repeatedly delivered to the shallow epithermal environment by “vapor-phase” metal (loid) transport. Full article
(This article belongs to the Special Issue Advances in Economic Minerals)

Journal Contact

MDPI AG
Minerals Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
minerals@mdpi.com
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Minerals
Back to Top