Abigail Jiménez Franco

Spanish National Research Council | CSIC · Institute of Geosciences Barcelona (GEO3BCN)

The Santa Fe mining district is located in the Central Andean tin belt of Bolivia and contains several Sn-Zn-Pb-Ag deposits. From the economic point of view, the most important deposits of the district are Japo, Santa Fe and Morococala. Beyond the traditional metal commodities, the Central Andean Tin Belt could become an exploration target for indi...

The Velardeña mining district is economically the most important of Durango state. The ore deposits occur in different skarn zones developed within the intrusive contact between Mesozoic limestones and Eocene granitic stocks and dikes. The most important ore deposits are related to the Santa María dike and Reyna de Cobre porphyritic stock (separate...

We report new results of a combined focused ion beam high-resolution transmission electron microscopy (FIB/HRTEM) investigation of two grains of platinum-group minerals (PGM) corresponding to the laurite (RuS2)-erlichmanite (OsS2) solid solution series. The grains are included within unaltered chromite and the serpentine-dominant matrix of the mant...

La zona geotérmica de Pathé (Hidalgo, México) presenta valores anómalos de mercurio atmosférico. Las anomalías detectadas (Hg en el aire) coinciden espacialmente con zonas de alteración argílica avanzada (antiguas minas de caolín); éstas constituyen fuentes naturales de emisiones de dicho metal pesado, cuyo enriquecimiento geológico se debe a los p...

Karstic bauxite deposits are the main resource of aluminum in Europe and are formed through a combination of weathering, leaching, and deposition processes known as bauxitization. Bauxites have recently been proposed as unconventional resources of rare-earth elements (REE) as well. The studied karstic bauxite deposits are located on the salt-detach...

Sulfur isotope study on polymetallic, In-bearing sulphide mineralizations from the Lovisa region, SE Finland.

Future engineers, in addition to technical knowledge, should incorporate in their academic curricula aspects that contribute to make mining a sustainable activity. This will contribute to changing the concept that society has about mining and to be a socially accepted activity. In the mining engineering studies at the Universitat Politècnica de Cat...

Gold was mainly concentrated in the Earth's solid and compacted Fe–Ni core during the planet’s accretionary stage, along with other highly siderophile elements. During partial melting of the mantle, gold is derived from the magmatic fluids that circulated to the surface in various tectonic contexts (cratons, ocean basins, divergent margins, converg...

Diamond ore deposits are confined to a few geological settings. Diamonds are typically found in ancient regions of the Earth’s crust, known as cratons. These are extensive parts that achieved long-term stability so have been poorly deformed over a long period.

Barite (barium sulfate) was assigned strategic mineral status by the EU in 2017.

Boron is widely distributed in the environment, including in soil, water, and animals, and it is essential to plant life.

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification. Besides, classifying REE ore deposits on the basis of only their genetic evolution would quickly induce misinterpretations. For instance, the class of copper-gold-uranium-REE-iron (IOCG) inc...

Elemental sulfur constitutes a metastable, intermediate state in the geological conversion of sulfate to sulfide or vice versa. Sulfur sedimentary deposits are formed from hydrogen sulfide resulting from the chemical reaction of sulfate with organic matter. Another possible sulfur origin was formed during or after formation of the enclosing rock. T...

Titanium is the ninth-most abundant element in Earth’s crust and, although it is not found as a pure metal in nature, it is found in nearly all rocks and sediments. It has a strong affinity for oxygen, typically forming oxide minerals, mainly ilmenite (FeTiO3) and rutile (TiO2) but also with other titanium dioxide polymorphs such as anatase and bro...

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification. Besides, classifying REE ore deposits on the basis of only their genetic evolution would quickly induce misinterpretations. For instance, the class of copper-gold-uranium-REE-iron (IOCG) inc...

Technetium-99 m is one of the most widely used radiopharmaceuticals (about 83%) in diagnostic procedures for organ functioning in the human body (heart, brain, thyroid, lungs, bones, and blood). This metastable isotope, with a half-life of 6 h, is injected into the patient and accumulates in several parts of the body, concentrating in altered parts...

According to USGS, most of the world’s gallium is from bauxite mining and from sphalerite. Bauxite deposits are traditionally regarded as the economic source of aluminum (Al); however, they are also an important source of gallium as a by-product, because its close geochemical affinity with Al enables gallium to substitute easily in rock-forming alu...

The platinum-group metals (PGMs) are found almost exclusively at very low concentrations in ores associated with mafic and ultramafic rocks. They can be subdivided into the Ir-subgroup (IPGE: Os, Ir, and Ru) and the Pt-subgroup (PPGE: Pt, Pd, and Rh). The most abundant PGM are the laurite–erlichmanite (RuS2–OsS2) series. These are commonly hosted i...

Fluorite occurs as an accessory mineral in granite, granite pegmatites, and syenites, and is also found in hydrothermal deposits. The following deposit types are in order of importance.

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification. Besides, classifying REE ore deposits on the basis of only their genetic evolution would quickly induce misinterpretations. For instance, the class of copper-gold-uranium-REE-iron (IOCG) inc...

Obtained from the water of some seas, from salt lakes, and from the brine associated with some oil deposits.

According to USGS (2021), germanium does not form specific deposits but occurs rather as a by-product in a variety of deposit types that contain copper, gold, lead, silver, and zinc. Germanium concentrations in sphalerite from these deposits are typically a few hundred parts per million. Because it is a by-product of metallurgical operations common...

Feldspars form an extensive group of silicate minerals. They constitute about 50% of the Earth’s crust, therefore they are found globally in igneous, metamorphic, and sedimentary rocks.

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification. Besides, classifying REE ore deposits on the basis of only their genetic evolution would quickly induce misinterpretations. For instance, the class of copper-gold-uranium-REE-iron (IOCG) inc...

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification. Besides, classifying REE ore deposits on the basis of only their genetic evolution would quickly induce misinterpretations.

Selenium is found in several deposit types, such as magmatic, volcanic, hydrothermal, and exogenic. It is found substituted into sulfide minerals such as chalcopyrite, cinnabar, cobaltite (CoAsS), galena, molybdenite, pentlandite, pyrite, pyrrhotite, sphalerite, and stibnite. Selenide minerals are less common than selenium-bearing sulfides, but pha...

The platinum-group metals (PGMs) are almost exclusively found at very low concentrations in ores associated with mafic and ultramafic rocks. They can be divided into the Ir-subgroup (IPGE: Os, Ir, and Ru) and the Pt-subgroup (PPGE: Pt, Pd, and Rh). PGMs are a group of six minerals in which at least one of the six is essential to the composition of...

The platinum-group metals (PGMs) are almost exclusively found at very low concentrations in ores associated with mafic and ultramafic rocks. They can be subdivided into two main groups: the Ir-subgroup (IPGE: Os, Ir, and Ru); and the Pt-subgroup (PPGE: Pt, Pd, and Rh). PGM minerals are a group in which at least one of the six PGM is essential to th...

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification. Besides, classifying REE ore deposits on the basis of only their genetic evolution would quickly induce misinterpretations. For instance, the class of copper-gold-uranium-REE-iron (IOCG) inc...

Thallium is mostly found in association with potassium minerals in clays, soils, and granites, but it is not commonly commercially recoverable from those sources. The major source of commercial thallium is trace amounts found in the sulfide ores of copper, lead, zinc, and other metals.

The main source of cesium is pollucite, a primary lithium-cesium-rubidium mineral. It is also found in association with lithium-rich, lepidolite-bearing, and petalite-bearing zoned granite pegmatites.

Phosphate deposits are widespread throughout the world, occurring on all continents and dating from the Precambrian to the Holocene. In terms of origin there are two main sources of phosphate deposit: sedimentary or igneous.

The main source of chlorine is halite (NaCl) and brines associated with the evaporitic deposits. Brine is a water solution with a high content of halite (NaCl), greater than 5%. The main halite deposits are saline flats characteristic of arid basins. They are shallow and dry apart from when storm flooding turns the saltpan and its surroundings into...

Known in the early fifteenth century, but was confused with lead and tin. In 1713 Claude Geoffroy the Younger (a French nobleman) identified it definitively.

The platinum-group metals (PGMs) are found almost exclusively at very low concentrations in ores associated with mafic and ultramafic rocks. They can be subdivided into the Ir-subgroup (IPGE: Os, Ir, and Ru) and the Pt-subgroup (PPGE: Pt, Pd, and Rh). The most abundant PGMs are in the laurite–erlichmanite (RuS2–OsS2) series. These are commonly host...

Hafnium is always found associated with zirconium, because of their similar geochemical behavior. Zircon (ZrSiO4) is the most common naturally occurring zirconium- and hafnium-bearing mineral. Most zircon forms as a product of primary crystallization in igneous rocks.

Approximately 90% of global production is from the Bayan Obo deposit in China, where scandium is a by-product of mining other REE and iron. It is hosted mostly by aegirine, although a small but significant proportion is present in bastnäsite-Ce, monazite-Ce, and fluorite.

Dolomite is a calcium magnesium carbonate with the chemical composition CaMg(CO3)2, constituting a rock-forming mineral found in abundance around the world. It has numerous commercial uses.

Tellurium is found mainly as epithermal deposits and occurs in telluride minerals as native tellurium, and as tellurium-bearing sulfosalts in unoxidized ores, as well as in the form of tellurites in secondary ores. Epithermal gold and silver deposits, such as sylvanite (Au,Ag)2Te4) and calaverite (AuTe2), can also be a source of tellurium, such as...

The primary mineral source of tin is cassiterite (SnO2). Tin’s mineralization is commonly associated with igneous intrusion and related ore systems. The classic tin deposit is greisen, an ore deposit characterized by a hydrothermally altered granitic rock. The mineralogical alteration is mostly composed of albite, quartz, and mica, common in Europe...

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification.

The main mineral source of sodium is halite. Halite can be found as a mineral (NaCl) or dissolved in water, forming brine. Brine is a solution with a high salt concentration, between 5% and 26 to 28%. Both halite and brine are closely associated with evaporite deposits, which may have either a lacustrine or marine origin.

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification. Besides, classifying REE ore deposits on the basis of only their genetic evolution would quickly induce misinterpretations. For instance, the class of copper-gold-uranium-REE-iron (IOCG) inc...

Stalactite and stalagmite formation in karst caves demonstrates the high of calcium carbonate content achieved over time by filtering water.

Andalusite is an aluminum silicate (Al2SiO5), sharing its chemical composition with kyanite and sillimanite. These three minerals are polymorphs, and are often summarized as the sillimanite minerals.

Zinc is most commonly found in hydrothermal veins. Zinc and lead are often found together, less so with copper and iron, in several kinds of ore deposits. Metals precipitate from ore fluids by various processes, depending on the specific local conditions.

Uranium occurs in a number of geological environments. The major uranium primaries ore minerals are uraninite (UO2) or pitchblende (U3O8). However, a range of other uranium minerals, such as carnotite (K2(UO2)2(VO4)2·3H2O) or brannerite (U,Ca,Y,Ce)(Ti,Fe)2O6 and secondary like gummite (secondary uranium oxides (yellow-orange)), autunite (Ca(UO2)2(P...

Silver is commonly found in hydrothermal veins. Gold and silver are often found together, less so with metals like lead, zinc, copper, and iron, in several kinds of ore deposits. Metals precipitate from ore fluids by various processes depending on specific local conditions. The most common processes are cooling, mixing with other fluids, and pH cha...

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification. Besides, classifying REE ore deposits on the basis of only their genetic evolution would quickly induce misinterpretations.

Corundum is an aluminum oxide (Al2O3). It is a relatively scarce mineral that appears in aluminous rocks, usually metamorphic, such as marbles, micaceous shales, and gneisses.

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification. Besides, classifying REE ore deposits on the basis of only their genetic evolution would quickly induce misinterpretations.

The main copper ores are chalcopyrite (CuFeS2) and bornite (Cu5FeS4). Porphyry systems are the main source of copper’s mineralization.

The primary ore of tantalum is the columbite-tantalite group. The columbite group is a solid solution with varying proportions of Nb or Ta in its composition. According to the International Mineralogical Association (IMA), ‘tantalite’ or ‘coltan’ are not scientific names, yet they are widely used. Many specimens commonly named tantalite are actuall...

Despite its abundance, it was considered a rare and expensive metal until 1886, when Charles M. Hall of the United States and Paul L. T. Héroult of France independently discovered an inexpensive system for obtaining pure aluminum by electrolysis of its oxide (Al2O3).

The platinum-group metals (PGMs) are found almost exclusively at very low concentrations in ores associated with mafic and ultramafic rocks. They can be divided into two main groups: the Ir-subgroup (IPGE: Os, Ir, and Ru) and the Pt-subgroup (PPGE: Pt, Pd, and Rh). The PGMs are a group for which at least one of the six minerals is essential to the...

Gutenberg, the inventor of the printing press (1450), created his mobile type from an antimony and lead alloy, giving greater hardness to the lead and allowing it to be used multiple times in linotypes. At the same time, it permitted rapid melting in case of deterioration or the need for new fonts.

The radium-223 isotope is made artificially from a generator containing actinium-227, similar to preparing technetium-99 m from molybdenum-99 (see: technetium).

Most cobalt deposits are associated with nickel deposits. These occur in two geological settings: magmatic sulfide deposits; and laterite deposits. Mines currently in operation exploit both kinds; however, laterite ore deposits comprise about 70% of known nickel–cobalt resources. Besides nickel and cobalt (frequently found in association), there ar...

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification. Besides, classifying REE ore deposits on the basis of only their genetic evolution would quickly induce misinterpretations. For instance, the class of copper-gold-uranium-REE-iron (IOCG) inc...

The primary mineral source of chromium (Cr) is chromite (Fe, Mg) Cr2O4. Chromite deposits can be classified into four deposit types: stratiform chromite; podiform chromite; placer chromite; and laterite.

A by-product of the extraction of zinc from zinc sulfides such as sphalerite.

Beryl in rare-metal pegmatites can occur with other minerals that contain commodities of commercial importance, such as cesium, lithium, and tantalum, as well as clay minerals, feldspar, muscovite, and high-purity quartz.

Obtained from arsenopyrite (iron arsenic sulfide), from nickel, cobalt, copper, and lead sulfides, as well as from realgar and orpiment, and from copper sulfides with gold.

Vanadium occurs in nature in a wide variety of minerals. The following four main types of mineral deposits are recognized: vanadiferous titanomagnetite (VTM); sandstone-hosted vanadium (SSV); shale-hosted; and vanadates.

A component of CO2 gas, a pollutant causing global warming, acid rain, and climate change. Our civilization is constantly emitting large amounts of CO2 from the combustion of fossil fuels (oil, coal, natural gas), in addition to natural emissions from volcanoes and animal and plant metabolism.

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification. Besides, classifying REE ore deposits on the basis of only their genetic evolution would quickly induce misinterpretations.

Limestone is a sedimentary rock comprised chiefly of calcium carbonate (CaCO3). Deposits are extensive around the world. Therefore, there is a high variability of limestone deposits. Typically, they are formed in two main environments.

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification. Besides, classifying REE ore deposits on the basis of only their genetic evolution would quickly induce misinterpretations. For instance, the class of copper-gold-uranium-REE-iron (IOCG) inc...

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification. Besides, classifying REE ore deposits on the basis of only their genetic evolution would quickly induce misinterpretations. For instance, the class of copper-gold-uranium-REE-iron (IOCG) inc...

Chuquicamata, in northern Chile, is the world’s largest porphyry copper ore body with molybdenite. Roasting the molybdenite emits gases, and the renium can then be extracted.

Graphite ore deposits fall into three main categories: microcrystalline graphite deposits, recently named ‘graphitic carbon’ (Beyssac O, Rumble D (2014) Elements 10(6): 415–420. https://doi.org/10.2113/gselements.10.6.415); disseminated flake-graphite; and chip graphite (Robinson Jr GR, Hammarstrom JM, Olson DW (2017) Graphite (No. 1802-J). US Geol...

The variations are substantial within the REE class of ore deposits, and the formation of an REE ore deposit gives little information about its classification. Besides, classifying REE ore deposits on the basis of only their genetic evolution would quickly induce misinterpretations. For instance, the class of copper-gold-uranium-REE-iron (IOCG) inc...

Zircon (ZrSiO4) is the most common naturally occurring zirconium-bearing mineral. Most zircon forms as a product of primary crystallization in igneous rocks, and it is always associated with hafnium. The world’s largest primary deposit of zirconium associated with alkaline igneous rocks is in a single locality on the Kola Peninsula of Murmanskaya O...

Rubidium replaces potassium or cesium in the composition of many minerals. Lepidolite ((KLi2Al(Al,Si)3O10(F,OH)2) is the most common source of rubidium. Rubidium also occurs in leucite (KAlSi2O6), carnallite (KCl · MgCl2 · 6(H2O)), zinnwaldite (KLiFeAl(AlSi3)O10(OH,F)2), and pollucite (Cs(Si2Al)O6 · nH2O). It is considered to be an incompatible ele...

Two strontium-bearing minerals, celestine (SrSO4) and strontianite (SrCO3), contain strontium in quantities sufficient to make their recovery worthwhile. Celestine is more common than strontianite and is the primary source of the world’s strontium. Celestine appears as crystals and as massive or fibrous aggregates in sedimentary rocks. It often dis...

The characteristic mineral source of potassium is sylvite (KCl). Sylvite is frequently observed associated with halite (NaCl), forming the mix known as sylvinite. In most cases, relatively pure sylvinite exists with essentially no soluble sulfate or other salts, yet it can occasionally be associated with carnallite (KMgCl3·6H20), with a similar cry...

The common mineral source of tungsten (W) is wolframite (Fe2+)WO4 to (Mn2+)WO4). Tungsten’s mineralization is commonly associated with igneous intrusion and related ore systems. The classic type of tungsten deposit is greisen, a kind of ore deposit characterized by a hydrothermally altered granitic rock.

Silica is present in multiple forms and minerals, but its most common form is quartz (SiO2). Quartz is the most abundant compound in the Earth’s crust, comprising roughly 14%. Quartz crystallization occurs when silica is heated. During the cooling process, silicon and oxygens recombine as molecules formed of one silicon atom and four oxygen atoms....

According to the International Atomic Energy Agency (IAEA), thorium does not occur in its metallic form in nature because it is markedly oxyphile, thus occurs as oxide (thorianite (ThO2)), silicates (thorite (Th,U)SiO4), and phosphates (frequently with rare earth elements).

Promethium is used as a source of beta radiation to measure thickness. It is deployed as a light source for signals that require reliable and independent operation, along with phosphorus, which absorbs beta radiation and produces phosphorescence light.

The Habana-Matanzas ophiolites (western Cuba) host several hydrothermal ultramafic-hosted Cu-Au-Co rich massive sulfide deposits (e.g. Loma Majana and Salomón). The ore mineralogy of these deposits consists of pyrrhotite, pyrite, and chalcopyrite, with minor Co-Fe-Ni arsenides/sulfarsenides (mainly safflorite and cobaltite), gold (electrum), and re...

The Velardeña mining district is economically the most important of Durango state. The ore deposits occur in different skarn zones developed within the intrusive contact between Mesozoic limestones and Eocene granitic stocks and dikes. The most important ore deposits are related to the Santa María dike and Reyna de Cobre porphyritic stock (separate...

The highly siderophile elements (HSE: Os, Ir, Ru, Rh, Pt, Pd, Re, Au) exist in solid solution in accessory base-metal sulfides (BMS) as well as nano-to-micron scale minerals in rocks of the subcontinental lithospheric mantle (SCLM). The latter include platinum-group minerals (PGM) and gold minerals, which may vary widely in morphology, composition...

This work provides the first ever nano-scale characterization of the zonation of Ru-Os sulphides of the solid solution series laurite (RuS2)-erlichmanite (OS2) in nature. These sulphides were found as solid inclusions within unaltered chromite forming chromitite ores of the Ojén ultramafic massif (Spain) and the Monte Bueno chromite deposit (Cuba)....

A significant amount of heavy metals, among them Hg, is emitted into the atmosphere from natural sources. However, the knowledge of Hg emissions from geothermal sources is still poorly investigated; they are therefore often considered as negligible contributors to the atmosphere. However, Bagnato et al. (2015) has reported up to 822 ngm-3 in the ai...

The tin-rich polymetallic epithermal deposit of Poopó, of plausible Late Miocene age, is part of the Bolivian Tin Belt. As an epithermal low sulfidation mineralisation, it represents a typological end-member within the "family" of Bolivian tin deposits. The emplacement of the mineralisation was controlled by the regional fault zone that constitutes...

INTRODUCCIÓN Hasta hace aproximadamente una década, las nanopartículas y nanominerales eran unos auténticos desconocidos en el ámbito de los yacimientos minerales. Sin embargo, el progresivo desarrollo de técnicas analíticas más potentes ha permitido caracterizar partículas cada vez de menor tamaño, lo cual ha llevado aparejado una verdadera explos...

Although nanoscale studies in minerals science have increased in the last decade, the number of publications in this field continue being scarce. By contrast, FIB/SEM/TEM techniques are now well established [1], especially for analysis of silicate minerals (e.g. [2]). Regard to ore minerals, recent studies have taken relevance, especially to explai...

Platinum-rich nanonuggets (s.l., nanoparticles) are commonly produced in experiments attempting to quantify the solubil-ity or partitioning of noble metals in silicate and sulfide melts. However, it has been thought that these represent artifacts produced during quenching of the experimental runs. Here, we document nanoparticles (~ 20-80 nm) of Pt-...

We report the first results of a combined focused ion beam and high-resolution transmission electron microscopy (FIB/HRTEM) investigation of zoned laurite (RuS 2)-erlichmanite (OS 2) in mantle-hosted chromitites. These platinum-group minerals form isolated inclusions (<50 µm across) within larger crystals of unaltered chromite form the Ojén ultrama...