Native tungsten (IMA2011-004), W, is officially described as a new mineral from gold placers in the Bol'shaya Pol'ya river valley, Prepolar Urals, Russia, associated with yttriaite-(Y) and from quartz veins in the Mt Neroyka rock-crystal field, Ust–Puiva, Tyumenskaya Oblast', Russia. Tungsten forms polycrystalline grains and masses, and rarely cubo-octahedra. It is silver white to steel grey in colour

At present, a significant portion of rare-earth elements (REEs) are sourced from weathering profiles. The mineralogy of the protolith plays an important role in controlling the fate of REEs during weathering, as accessory minerals contain the bulk the REE budget in most rocks, and different minerals vary in their susceptibilities to weathering processes. REE supergene deposits (‘adsorption clay deposits’)

Manganese (Mn) oxides have been prevalent on Earth since before the Great Oxidation Event and the Mn cycle is one of the most important biogeochemical processes on the Earth's surface. In sunlit natural environments, the photochemistry of Mn oxides has been discovered to enable solar energy harvesting and conversion in both geological and biological systems. One of the most widespread Mn oxides is

Finely laminated (cm–μm scale) metalliferous precipitates are widespread in the surficial environment, especially around mineral deposits and reflect biogeochemical processes that can pervade near-surface environments on a larger scale. Examples in this paper involve precipitates of the transition metals Fe, Cu and Mn with minor Co, Ni, V and Zn; the metalloids As and Sb; and authigenic Au. Mobility

The new mineral hrabákite (IMA2020-034) was found in siderite–sphalerite gangue with minor dolomite–ankerite at the dump of shaft No. 9, one of the mines in the abandoned Příbram uranium and base-metal district, central Bohemia, Czech Republic. Hrabákite is associated with Pb-rich tučekite, Hg-rich silver, stephanite, nickeline, millerite, gersdorffite, sphalerite and galena. The new mineral occurs

The new alluaudite-group mineral calciojohillerite is one of the major arsenates in sublimates of the Arsenatnaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. In middle zones of the fumarole, calciojohillerite is associated with hematite, tenorite, johillerite, nickenichite, bradaczekite, badalovite, tilasite

The Quaternary carbonatite–nephelinite Kerimasi volcano is located within the Gregory rift in northern Tanzania. It is composed of nephelinitic and carbonatitic pyroclastic rocks, tuffs, tuff breccias and pyroclastic breccias, which contain blocks of different plutonic (predominantly ijolite) and volcanic (predominantly nephelinite) rocks including carbonatites. The plutonic and volcanic carbonatites

The paper presents detailed mineralogical and structural characteristics of novograblenovite that occurs abundantly on a burning coal dump at Radlin, Upper Silesia, Poland. Our results indicate that NH4MgCl3⋅6H2O is the proper formula of this mineral. The thermal behaviour of novograblenovite shows a two-step dehydration at 155 and 193°C and sublimation of NH4Cl at 341°C. A Raman spectrum, obtained

The paper investigates trace elements and crystal-rich fluid inclusions in spodumene from rare-metal pegmatites of the Kolmozero lithium deposit in the Kola region, Russia. The main lithium mineral in the pegmatites is spodumene, which occurs in three generations, designated as Spd-I, Spd-II and Spd-III. Iron, Na and Mn are the most typical element impurities in spodumene. The Fe/Mn ratio is 7.1 in

Rare earth elements (REEs, ‘lanthanides’) constitute a vital commodity for technological applications. Although these elements occur at trace levels in many minerals, they can comprise major constituents of low abundance phosphate, carbonate, silicate and oxide minerals, some of which form during granite weathering. REE-phosphate phases can be a source of phosphorus for essential biomolecules and certain

An unusual highly hydrated and Na-depleted variety of elpidite was identified in a hydrothermally altered peralkaline pegmatite at Mt. Yukspor in the Khibiny alkaline complex, Kola Peninsula, Russia. It differs from ‘ordinary’ elpidite, ideally Na2ZrSi6O15⋅3H2O, in its crystal chemical features, infrared spectrum and optical characteristics. The chemical composition (wt.%, electron microprobe, H2O

Panskyite, Pd9Ag2Pb2S4, is a new mineral (IMA2020–039) discovered in the platinum-group element mineralisation of the Southern Kievey ore occurrence of the Fedorova–Pana layered intrusion, Kola Peninsula, Russia. It forms tiny anhedral grains (of 0.5 to 10 μm in size) in the interstices of rock-forming silicates, often forming tiny inclusions in base-metal sulfides (millerite, chalcopyrite, bornite

Galeaclolusite, [Al6(AsO4)3(OH)9(H2O)4]⋅8H2O, is a new secondary hydrated aluminium arsenate mineral from Cap Garonne, Var, France. It forms crusts and spheroids of white fibres up to 50 μm long by 0.4 μm wide and only 0.1 μm thick. The fibres are elongated along [001] and flattened on (100). The calculated density is 2.27 g⋅cm–3. Optically, galeaclolusite is biaxial with α = 1.550(5), β not determined

A major debris flow, the Trig Point Hill flow, originating from Kerimasi volcano (Tanzania) contains numerous blocks of extrusive/pyroclastic carbonatites similar to those exposed at the rim of the currently inactive crater. The blocks of calcite carbonatite consist of: (1) large clasts of corroded and altered coarse grained calcite; (2) primary prismatic inclusion bearing phenocrystal calcite; and

Molecular formulae used to recalculate nepheline analyses generally have different numbers of oxygens (e.g. NaAlSiO4 (Ne), KAlSiO4, (Ks), CaAl2Si2O8 (An) and SiO2 (Q)). A 32 oxygen cell has 16 T cations and 8 cavity sites, but ideal nepheline stoichiometry is not necessarily followed. Ca end-member □CaCaAl2Si2O4 (CaNe) and excess silica end-member □SiSi2O4 (Q’) calculation requires inclusion of both

Thermal behaviour of fibrous tremolite from Maryland, USA has been investigated in situ up to breakdown temperature. Tremolite can be found both as primary constituent and as contaminant in Asbestos Containing Materials (ACMs). The products of breakdown are subcalcic diopside and calcium-rich clinoenstatite in a 2:1 ratio, traces of hematite plus minor silica-rich amorphous material. Thermal expansion

A new arrojadite-group mineral manganoarrojadite-(KNa), ideally KNa5MnFe13Al(PO4)11(PO3OH)(OH)2, was found in a phosphate-bearing granite pegmatite at the Palermo No. 1 mine, New Hampshire, USA. It forms anhedral grains up to 1 × 1.5 cm in size combined in aggregates with vivianite, goyazite, quartz and calcite. The mineral is olive green with a pale green streak and vitreous to greasy lustre. The

Bosoite (IMA2014-023) is a new silica clathrate mineral containing hydrocarbon molecules in its crystal structure. Bosoite can be considered structurally as a silica analogue of the structure-H gas hydrate, where guest molecules are trapped in cage-like voids constructed of the host framework. The mineral occurs in the Miocene tuffaceous sedimentary rocks at Arakawa, Minami-boso City, Chiba Prefecture

Zircon crystals from diamondiferous kyanite gneisses of the Barchi-Kol area (Kokchetav massif, Northern Kazakhstan) have been investigated by a combined application of cathodoluminescence (CL), Raman spectroscopy and electron probe microanalysis (EPMA). The zircon crystals exhibit up to four distinct domains characterised by significantly different CL signatures and parameters of the ν3(SiO4) (1008

Jeankempite, Ca5(AsO4)2(AsO3OH)2(H2O)7, is a new mineral species (IMA2018-090) discovered amongst coatings of arsenate minerals on oxidised copper arsenides from the Mohawk No. 2 mine, Mohawk, Keweenaw County, Michigan, USA. The new mineral occurs as lamellar bundles of colourless to white plates up to 1 mm wide and is visually indistinguishable from guérinite, with which it forms intergrowths. Jeankempite

The line connecting rare earth elements (REE) in chondrite-normalised plots can be represented by a smooth polynomial function using λ shape coefficients as described by O'Neill (2016). In this study, computationally generated λ combinations are used to construct artificial chondrite-normalised REE patterns that encompass most REE patterns likely to occur in natural materials. The dominant REE per

Kagomé nets of corner-connected triangles of atoms occur in diverse minerals, from the {111} anion arrays in perovskite-group minerals to natural metallic alloys like auricupride, AuCu3, to the cation layers in atacamite-group minerals. We review here two- and three-dimensional kagomé networks in minerals where the kagomé node atoms are octahedrally coordinated in hexagonal tungsten bronze (HTB) arrays

The metamorphic history of the Mesoarchean Amikoq Layered Complex within the Akia terrane of SW Greenland was characterised by electron microprobe mineral data and detailed petrography on 12 representative samples, integrated with zircon U–Pb geochronology and petrology. The complex intruded into a >3004 Ma supracrustal association now consisting of granoblastic metabasites with subordinate quartz-rich

Orthopyroxene-bearing felsic gneiss occurs as foliation-parallel layers and bands together with aluminous granulite, mafic granulite, and quartzofeldspathic granulite in the Chilka Lake migmatite complex of the Proterozoic Eastern Ghats Belt, India. The rock was classified previously as charnockite which underwent granulite-facies metamorphism. Field and textural features of this rock show evidence

A new mineral species of the pyrochlore supergroup, hydroxyplumbopyrochlore (IMA2018-145), (Pb1.5,□0.5)Nb2O6(OH), has been discovered in the Jabal Sayid peralkaline granitic complex of the Arabian Shield, Saudi Arabia. It is associated with quartz, microcline, ‘biotite’, rutile, zircon, calcite, rhodochrosite, columbite-(Fe), goethite, thorite, bastnäsite-(Ce), xenotime-(Y), samarskite-(Y), euxenite-(Y)

This work presents a detailed study of platinum-group mineral (PGM) assemblages from the Malaya Kamenushka River placer, whose formation is associated with the weathering of the Kamenushensky Uralian–Alaskan type massif, Middle Urals, Russian Federation. The deposit is characterised by the dominance of isoferroplatinum, together with significant numbers of inclusions of Os–Ir–Ru alloys and platinum-group

The new triazolate mineral bojarite (IMA2020-037), Cu3(N3C2H2)3(OH)Cl2⋅6H2O, is found in a guano deposit located at the Pabellón de Pica Mountain, Iquique Province, Tarapacá Region, Chile. Associated minerals are salammoniac, halite, nitratine and belloite. Bojarite occurs as blue fine-grained porous aggregates up to 1 mm × 3 mm × 5 mm combined typically in interrupted earthy crusts. The mineral is

The cerite supergroup is established and includes the cerite group (silicates) and merrillite group (phosphates). Cerite-group minerals are cerite-(Ce), ferricerite-(La), aluminocerite-(Ce) and taipingite-(Ce). The merrillite group is subdivided into two subgroups: merrillite (merrillite, ferromerrillite, keplerite and matyhite) and whitlockite (whitlockite, strontiowhitlockite, wopmayite and hedegaardite)

The assayers’ ingots recovered in 2014 from the SS Central America contain geochemical signatures and anomalies which convey information about the culture of miners and assayers in the late 1850s. A significant number of ingots (21%) contain elevated copper and zinc in the same ratio as a common brass alloy of the period, suggesting that adulteration of placer gold dust was a common issue. The ingots

A green tourmaline sample from the Tzarevskoye uranium–vanadium deposit, close to the Srednyaya Padma deposit, Lake Onega, Karelia Republic, Russia, has been found to be the second world-occurrence of Cr-rich vanadio-oxy-dravite in addition to the Pereval marble quarry, Sludyanka crystalline complex, Lake Baikal, Russia, type-locality. From the crystal-structure refinement and chemical analysis, the

The new mineral percleveite-(La) (IMA2019–037), ideally La2Si2O7, was found in polymineralic nodules of the Mochalin Log REE deposit, Chelyabinsk Oblast, South Urals, Russia. It is associated with allanite-(Ce), allanite-(La), bastnäsite-(Ce), bastnäsite-(La), ferriallanite-(Ce), ferriallanite-(La), ferriperbøeite-(Ce), ferriperbøeite-(La), fluorbritholite-(Ce), hydroxylbastnäsite-(Ce), perbøeite-(Ce)

Galena–tetrahedrite intergrowth textures have been observed in some quenched run products of melting experiments conducted at 500 and 600°C in the systems ZnS–PbS–FeS–Cu2S–Sb2S3 and ZnS–PbS–FeS–Cu2S–Sb2S3–As2S3, using the evacuated silica-tube method. At 600°C the intergrowth formed an interface between sulfide melt and galena, whereas at 500°C it existed as inclusions partially embedded or completely

Thunderbayite (IMA2020–042), ideally TlAg3Au3Sb7S6, is a new mineral from the Hemlo gold deposit, Marathon, Ontario, Canada. It occurs as very rare anhedral rims up to 70 μm across in contact with aurostibite and associated spatially with stibarsen, biagioniite and native gold in a calcite matrix. Thunderbayite is opaque with a metallic lustre and shows a black streak. In reflected light, thunderbayite

Monteneroite (IMA2020-028), Cu2+Mn2+2(AsO4)2⋅8H2O, is a new vivianite-structure mineral from the Monte Nero mine, Rocchetta di Vara, La Spezia, Liguria, Italy. It is a secondary mineral that crystallised from As-, Cu- and Mn-rich fluids and it is associated with braunite, copper, cuprite, rhodochrosite and strashimirite. Monteneroite occurs as light green, thick blades up to ~2.5 mm long. The streak

The rhodonite-group mineral with the idealised, end-member formula MnMn4[Si5O15] and the crystal chemical formula VIIM(5)MnVIM(1–3)Mn3VIIM(4)Mn[Si5O15] (Roman numerals indicate coordination numbers) is defined as a valid mineral species named vittinkiite after the type locality Vittinki (Vittinge) mines, Isokyrö, Western and Inner Finland Region, Finland. Vittinkiite is an isostructural analogue of

Oxycalciomicrolite (IMA2019-110), (Ca,Na)2(Ta,Nb,Ti)2O6(O,F), is a new member of microlite-group mineral found in the saprolite of the weathered Fumal pegmatite, located close to the city of Nazareno, Minas Gerais state, Brazil. It occurs as an accessory mineral associated with quartz, albite, microcline, muscovite, columbite-subgroup minerals, cassiterite, hematite, ilmenite, monazite-(Ce), xenotime-(Y)

The occurrence and characterisation of a new member of the dundasite group are reported. Grguricite, ideally CaCr2(CO3)2(OH)4⋅4H2O, is the Cr analogue of alumohydrocalcite, CaAl2(CO3)2(OH)4⋅4H2O and occurs as lilac crusts of very fine-grained crystalline aggregates in the Pb–Ba–V mineralisation found at the Adeghoual Mine, Mibladen, Morocco (32°46′0″N, 4°37′59″W). The identification was based upon

New occurrences of derbylite, Fex2+Fe3+4–2xTi4+3+xSb3+O13(OH), and graeserite, Fex2+Fe3+4–2xTi4+3+xAs3+O13(OH), have been identified in the Monte Arsiccio mine, Apuan Alps, Tuscany, Italy. Derbylite occurs as prismatic to acicular black crystals in carbonate veins. Iron and Ti are replaced by V (up to 0.29 atoms per formula unit, apfu) and minor Cr (up to 0.04 apfu). Mössbauer spectroscopy confirmed

The Open Access movement has gathered significant momentum over the last couple of years. This has been instigated largely by cOAlition S and those funders which support its aims. Is ‘Read and Publish’ the way forward? Will it work for all publishers? All authors? All subscribers? All readers? This article looks at the history of OA and updates a similar piece from 2013. A detailed glossary of terms

Witherite originates from the biochemical sedimentation of barium in sea water. Due to the complexity of the metallogenic environment, witherite appears in many morphologies. However, the relationship between its diverse morphologies and its mineralisation environment is not well understood. In this paper, Ca2+, a common substitute for Ba2+, and mixed protein (egg white) were used to simulate the inorganic

Khademite, ideally Al(SO4)F(H2O)5, from the Monte Arsiccio mine, Apuan Alps, Tuscany, Italy, has been characterised through quantitative electron microprobe analysis, micro-Raman spectroscopy and single-crystal X-ray diffraction. Khademite occurs as colourless to whitish tabular crystals, up to 5 mm. Electron microprobe analysis (in wt.%, average of 20 spot analyses) gave: SO3 35.43, Al2O3 21.27, F

Biogenic nanoscale vanadium magnetite is produced by converting V(V)-bearing ferrihydrites through reductive transformation using the metal-reducing bacterium Geobacter sulfurreducens. With increasing vanadium in the ferrihydrite, the amount of V-doped magnetite produced decreased due to V-toxicity which interrupted the reduction pathway ferrihydrite–magnetite, resulting in siderite or goethite formation

We report the crystal structures of four synthetic members of the variscite group (space group type Pbca) and of bonacinaite, the first naturally occurring scandium arsenate member of the metavariscite group. All structures were determined using single-crystal X-ray intensity data. The following members were all synthesised under either mild hydrothermal conditions or by wet-chemical methods (<90°C)

Bulachite specimens from Cap Garonne, France, comprise two intimately mixed hydrated aluminium arsenate minerals with the same Al:As ratio of 2:1 and with different water contents. The crystal structures of both minerals have been solved using data from low-dose electron diffraction tomography combined with synchrotron powder X-ray diffraction. One of the minerals has the same powder X-ray diffraction

The crystal structure of arsenopalladinite, Pd8As2.5Sb0.5, from the Kaarreoja River, Inari commune, Finnish Lapland, Finland, was solved to R1 = 0.0451 on the basis of single-crystal X-ray diffraction data. The mineral is triclinic, space group P $\bar{1}$ . The unit-cell parameters are: a = 7.3344(7), b = 7.3870(8), c = 7.5255(7) Å, α = 98.869(8), β = 102.566(8), γ = 119.096(11)°, V = 331.19(7) Å3

Two new isostructural minerals radekškodaite-(La) (CaLa5)(Al4Fe2+)[Si2O7][SiO4]5O(OH)3 and radekškodaite-(Ce) (CaCe5)(Al4Fe2+)[Si2O7][SiO4]5O(OH)3 were discovered in polymineralic nodules from the Mochalin Log REE deposit, South Urals, Russia. Radekškodaite-(La) is associated with allanite-(Ce), allanite-(La), bastnäsite-(Ce), bastnäsite-(La), ferriallanite-(Ce), ferriallanite-(La), ferriperbøeite-(La)

Alstonite, BaCa(CO3)2, is a mineral described almost two centuries ago. It is widespread in Nature and forms magnificent cm-sized crystals. Notwithstanding, its crystal structure was still unknown. Here, we report the crystal-structure determination of the mineral and discuss it in relationship to other polymorphs of BaCa(CO3)2. Alstonite is trigonal, space group P31m, with unit-cell parameters a =

The new minerals natromarkeyite, Na2Ca8(UO2)4(CO3)13(H2O)24⋅3H2O (IMA2018-152) and pseudomarkeyite, Ca8(UO2)4(CO3)12(H2O)18⋅3H2O (IMA2018-114) were found in the Markey mine, San Juan County, Utah, USA, where they occur as secondary phases on asphaltum. Natromarkeyite properties are: untwinned blades and tablets to 0.2 mm, pale yellow green colour; transparent; white streak; bright bluish white fluorescence

Petrovite, Na10CaCu2(SO4)8, is a new sulfate mineral discovered on the Second scoria cone of the Great Tolbachik fissure eruption. The mineral occurs as globular aggregates of tabular crystals up to 0.2 mm in maximal dimension, generally with gaseous inclusions. The empirical formula calculated on the basis of O = 32 is Na6(Na1.80K0.20)Σ2Na(Ca0.82Na0.06Mg0.02)Σ0.90(Cu1.84Mg0.16)Σ2(Na0.52□0.48)Σ1S8

The new mineral isselite, Cu6(SO4)(OH)10(H2O)4⋅H2O, has been discovered in the Lagoscuro mine, Monte Ramazzo mining complex, Genoa, Eastern Liguria, Italy. It occurs as sprays of blue acicular crystals, up to 0.1 mm long, associated with brochantite and posnjakite. Streak is light blue and the lustre is vitreous. Isselite is brittle, with irregular fracture and good cleavage on {001} and {100}. Measured

Preferential removal of W relative to other trace elements from zoned, W–Sn–U–Pb-bearing hematite coupled with disturbance of U–Pb isotope systematics is attributed to pseudomorphic replacement via coupled dissolution reprecipitation reaction (CDRR). This hematite has been studied down to the nanoscale to understand the mechanisms leading to compositional and U/Pb isotope heterogeneity at the grain

Luboržákite, ideally Mn2AsSbS5, is a new mineral from the Vorontsovskoe gold deposit, Northern Urals, Russia. It forms long-prismatic crystals up to 70 × 20 μm and anhedral grains of the same size embedded in the matrix of Mn-bearing dolomite and Mn-bearing calcite. Associated minerals include pyrite, orpiment, realgar, stibnite, aktashite, alabandite, boscardinite, chabournéite, coloradoite, clerite

The new leucophosphite-group mineral ammoniotinsleyite is found in a guano deposit located on the Pabellón de Pica Mountain, Iquique Province, Tarapacá Region, Chile. Associated minerals are halite, gypsum, salammoniac and clay minerals. Ammoniotinsleyite occurs as pink to pale violet globular aggregates up to 3 mm across with individual single crystals ~10–15 μm. The mineral is brittle. Its Mohs hardness

The new mineral fluorapophyllite-(NH4), ideally NH4Ca4(Si8O20)F⋅8H2O, was found at the Vechec andesite quarry located near Vechec village, Vranov nad Topľou Co., Prešov Region, Slovak Republic. It occurs in cavities of quartz–illite–saponite–tobelite xenolith embedded in pyroxene andesite. Fluorapophyllite-(NH4) is associated with calcite, tridymite, pyrite, chabazite-Ca and heulandite-Ca. It forms

The new alluaudite-group mineral badalovite was found in the Arsenatnaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. It is associated with hematite, tenorite, cassiterite, johillerite, nickenichite, calciojohillerite, bradaczekite, metathénardite, aphthitalite, langbeinite, calciolangbeinite, sanidine

The paper opens a series devoted to the mineral diversity of the Mochalin Log rare earth element (REE) deposit, South Urals, Russia. There is a brief outline of the history of studies and geology of the deposit as well as the description of two new isostructural gatelite-group minerals, ferriperbøeite-(La) (CaLa3)(Fe3+Al2Fe2+)[Si2O7][SiO4]3O(OH)2 and perbøeite-(La) (CaLa3)(Al3Fe2+)[Si2O7][SiO4]3O(OH)2

Jahnsite-(CaMnZn), CaMn2+Zn2Fe3+2(PO4)4(OH)2⋅8H2O, is a new jahnsite-group mineral associated with alteration of phosphophyllite at the Hagendorf-Süd pegmatite, Bavaria. It forms as thin yellow crusts and brown epitactic growths on altered phosphophyllite, both of which comprise lath-like crystals in orthogonal orientation, up to 100 μm long. The crystals contain intergrowths of jahnsite-(CaMnZn) and

The crystal structure of pyrostilpnite from the Plaka mine, Lavrion Mining District, Greece, was refined in the space group P21/c to a final R1 index of 0.0283 on the basis of 2047 reflections with Fo > 4σ(Fo) and 65 refined parameters. Unit-cell parameters of the crystal examined are a = 6.8629(6), b = 15.8800(14), c = 6.2711(5) Å, β = 117.087(2)°, V = 608.48(9) Å3 and Z = 4. Chemical data agree with

Tetrahedrite-(Hg), Cu6(Cu4Hg2)Sb4S13, has been approved as a new mineral species using samples from Buca della Vena mine (hereafter BdV), Italy, Jedová hora (Jh), Czech Republic and Rožňava (R), Slovakia. It occurs as anhedral grains or as tetrahedral crystals, black in colour, with metallic lustre. At BdV it is associated with cinnabar and chalcostibite in dolomite veins. At Jh, tetrahedrite-(Hg)

A new mineral glikinite, ideally Zn3O(SO4)2, was found in high-temperature exhalative mineral assemblages in the Arsenatnaya fumarole, Second scoria cone of the Great Tolbachik Fissure Eruption (1975–1976), Tolbachik volcano, Kamchatka Peninsula, Russia. Glikinite is associated closely with langbeinite, lammerite-β, bradaczekite, euchlorine, anhydrite, chalcocyanite and tenorite. It is monoclinic,