Jakub Plasil

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• PhD in Geosciences
• Senior Researcher at Czech Academy of Sciences, Institute of Physics

A rare silver mineral, dervillite (ideally Ag 2 AsS 2), has been found in specimens from the famous Jáchymov mining district, Czech Republic. It occurs as very rare long-prismatic crystals up to 0.4 mm across in association with proustite, bismuth and native silver in the thin arsenic veinlets within the Trojická vein (Svornost mine). Dervillite is...

Škáchaite (IMA 2022-143) is a new mineral species discovered in samples from the hydrothermal vein B117, shaft No. 6 at the Brod deposit of the uranium and base-metal Příbram ore district, central Bohemia, Czech Republic. Škáchaite forms anhedral grains up to 50 μm in size and 20-100 μm thick growth zones in škáchaite-dolomite crystals as a part o...

Lazerckerite, ideally Ag3.75Pb4.5(Sb7.75Bi4)S24, is a new mineral species found in medieval mine dumps of the historic Ag–Pb–Zn Kutná Hora ore district, Czech Republic. The mineral is associated with other Sb–Bi lillianite homologues (terrywallaceite, gustavite, holubite) and Ag,Bi-bearing galena, most frequently as grain aggregates and replacement...

The new mineral bobfinchite (IMA2020-082), Na[(UO2)8O3(OH)11]·10H2O, was found in the Burro mine, Slick Rock district, San Miguel County, Colorado, U.S.A., where it occurs as an oxidation product of uraninite on asphaltite matrix in intimate association with gypsum, natrozippeite, metaschoepite, and uranopilite. Bobfinchite crystals are transparent...

Although uranium oxide hydrate (UOH) minerals and synthetic phases have been extensively studied, the role of ammonium ions in the formation of UOH materials is not well understood. In this work, the stabilization of a synthetic UOH phase with ammonium ions and the inclusion of ammonium nitrate were investigated using a range of structural and spec...

Uramphite, (NH4)(UO2)(PO4) · 3H2O, was found at Beshtau uranium deposit, Northern Caucasus, Russia, as the second world occurrence besides its type locality, Tura-Kavak uranium-coal deposit in Kyrgyzstan. In Beshtau, it occurs as yellow tabular crystals up to 0.3 mm grouped in crusts on a matrix composed of albite, microcline, quartz and chamosite...

The new mineral theuerdankite, ideally Ag3AsO4, was found in the Alter Theuerdank Mine,Beerberg, St. Andreasberg, Goslar District, Lower Saxony, Germany. Theuerdankite occurs as aggregates of anhedral grains up to 3 mm in size, growing in cavities of strongly supergene-weathered material consisting of native silver and chlorargyrite (but with calci...

Zipserite is a new mineral species discovered in a sample collected from the old mine dumps of the abandoned epithermal deposit Nagybörzsöny in Hungary. Zipserite occurs as anhedral to subhedral, lath-like grains, up to 500 μm in size, in hydrothermally strongly altered rocks. It is found at a contact between bismuth and bismuthinite, also associat...

Znucalite is a zinc uranyl-carbonate mineral that was until recently only partially characterized with a formula originally given as Zn12Ca(UO2)(CO3)3(OH)22·4H2O, with an unknown crystal structure and ambiguous symmetry determinations. We have reinvestigated this mineral using three-dimensional electron diffraction (3D ED) and powder X-ray diffract...

We studied a rare magnesium uranyl sulphate mineral, chenowethite, from the Jáchymov ore district, Krušné hory Mountains (Czech Republic). It was confirmed from the two samples originating from the Svornost mine in Jáchymov. Chenowethite forms rich crystalline aggregates on supergene-altered rocks in association with dark yellow to orange mineral o...

Neustädtelite and not-yet approved Zn-analogue of neustädtelite (Zn-neustädtelite) were found in material from the Geister vein, western part of the Jáchymov ore district, the Krušné hory Mts., Czech Republic. Neustädtelite occurs as orange brown crystalline aggregates in association with walpurgite, bismutite, eulytine, preisingerite and zavaritsk...

The new mineral libbyite (IMA2022-091), (NH4)2(Na2□)[(UO2)2(SO4)3(H2O)]2·7H2O, was found in the Blue Lizard mine, San Juan County, Utah, USA, where it occurs as tightly intergrown aggregates of light green-yellow equant crystals in a secondary assemblage with bobcookite, coquimbite, halotrichite, metavoltine, rhomboclase, römerite, tamarugite, volt...

Shinkolobweite, Pb1.333[U5+O(OH)(UO2)5O4.67(OH)5.33](H2O)5, is a new lead uranyl oxide-hydroxide hydrate mineral containing hexavalent and pentavalent uranium from the Shinkolobwe mine, Democratic Republic of Congo. Crystals of shinkolobweite are dark reddish-brown prisms up to 0.5 mm in length, occurring on a matrix of massive uraninite associated...

Enargite (Cu3AsS4) and tennantite (Cu12As4S13) are typical As-bearing sulfides in intermediate- and high-sulfidation epithermal deposits. Trace and major element variations in enargite and tennantite and their substitution mechanisms are widely described. However, Raman spectra of the minerals with correlative quantitative chemical information are...

Although barium(II) ions play an important role in the natural weathering of the mineral uraninite (UO 2+x ) and are expected to therefore do the same for spent nuclear fuel in geological...

Prachařite, ideally CaSb⁵⁺2(As³⁺2O5)2O2·10H2O, is a new mineral found in underground workings of the Plaka Mine No. 80, Plaka, Lavrion Mining District, Attica, Greece. It occurs as colourless to white, thin tabular hexagonal, in general sharp crystals up to 2.5 mm in diameter, and is associated with pharmacolite, sulphur and very rare smamite {Ca2S...

The new mineral shinarumpite (IMA2021-105), [Co(H 2 O) 6 ][(UO 2 )(SO 4 ) 2 (H 2 O)]⋅4H 2 O, was found in the Scenic mine on Fry Mesa, White Canyon district, San Juan County, Utah, USA, where it occurs as a secondary phase on granular quartz matrix in association with gypsum, deliensite, Co-rich rietveldite, scenicite, shumwayite and sulfur. Shinar...

A new mineral species, holubite, ideally Ag 3 Pb 6 (Sb 8 Bi 3 ) Σ11 S 24 , has been found at Kutná Hora ore district, Czech Republic. The mineral is associated with other lillianite homologues (gustavite, terrywallaceite, vikingite and treasurite) most frequently as grain aggregates and replacement rims of earlier Ag–Pb–Bi minerals, growing togethe...

We present the crystallographic program J ana 2020, the successor of J ana 2006. J ana 2020 has new, technically different graphics and structure plot-driven intuitive control. Tools known from J ana 2006 were revised and inserted into a new logical scheme, and their control connected with the structure plot. Some of the tools were considerably imp...

Many natural secondary arsenates contain a small fraction of phosphate. In this work, we investigated the olivenite–libethenite (Cu2(AsO4)(OH)–Cu2(PO4)(OH)) solid solution as a model system for the P–As substitution in secondary minerals. The synthetic samples spanned the entire range from pure olivenite (Xlib=0) to libethenite (Xlib=1). Acid-solut...

The new mineral zincorietveldite (IMA2022-070), Zn(UO 2 )(SO 4 ) 2 (H 2 O) 5 , was found in the Blue Lizard mine, San Juan County, Utah, USA, where it occurs as yellow to orange–yellow blades in a secondary assemblage with bobcookite, coquimbite, halotrichite, libbyite, metavoltine, rhomboclase, römerite, tamarugite and voltaite. The streak is very...

Secondary minerals, especially phosphates and arsenates of copper and zinc, form a group of phases with astonishing variability in crystal structures and chemical composition. Some of these minerals are more common than others and one has to ask whether the abundance is linked to their thermodynamic stability or rather to geochemical constraints. I...

Oldsite (IMA2021–075), ideally K2Fe2+[(UO2)(SO4)2]2(H2O)8, is a new uranyl sulfate mineral found on specimens from the North Mesa Mine group, Temple Mountain, San Rafael district, Emery County, Utah, USA. It is a secondary mineral occurring with alum-(K), halotrichite, metavoltine, quartz, römerite, stanleyite, sulfur, szomolnokite, and mathesiusit...

The new mineral argentopolybasite, ideally Ag16Sb2S11, was found at the Kremnica Au-Ag epithermal deposit, Žiar nad Hronom Co., Banská Bystrica Region, Slovakia (type locality), Šibeničný vrch near Nová Baňa, Žarnovica Co., Banská Bystrica Region, Slovakia (cotype locality) and the Arykevaam epithermal Au-Ag deposit, Anadyr’ District, Chukotka Auto...

Fluorpyromorphite, ideally Pb 5 (PO 4) 3 F, a new apatite-group member, an F-dominant analog of pyromorphite and hydrox-ylpyromorphite. It is a supergene mineral found at two localities: Sukhovyaz Mountain, Ufaley District, Southern Urals (holotype) and Mountain 1004, Tolbachik volcano, Kamchatka (co-type), both in Russia. At Sukhovyaz, fluorpyromo...

We have undertaken a study of the rare ammonium uranyl sulphate mineral, ammoniozippeite, from the Jáchymov ore district, Krušné hory Mountains (Czech Republic). It has been found on a few specimens and forms rich crystalline aggregates in thin cracks of supergene altered rocks with uraninite veinlets in association with gypsum. Its radially arrang...

Synthetic samples of krautite, Mn[AsO 3 (OH)]·H 2 O, koritnigite, Zn[AsO 3 (OH)]·H 2 O, and cobaltkoritnigite, Co[AsO 3 (OH)]·H 2 O, were used for calorimetric experiments. For krautite and koritnigite, single-crystal X-ray diffraction was used to determine positions of all atoms, including the H atoms. These data allowed to determine the hydrogen-...

Argentotetrahedrite-(Cd), Ag6(Cu4Cd2)Sb4S13, has been approved as a new mineral species by the International Mineralogical Association - Commission on New Minerals, Nomenclature and Classification (IMA-CNMNC) using samples from Rudno nad Hronom, Slovak Republic. It occurs as anhedral grains up to 30 μm in size, steel-grey to black in colour, with a...

The new mineral chenowethite, Mg(H2O)6[(UO2)2(SO4)2(OH)2]·5H2O, was found in efflorescence crusts on tunnel walls at the Blue Lizard, Green Lizard and Markey uranium mines in Red Canyon, San Juan County, Utah, USA. The crystals are long, thin blades up to about 0.5 mm long, occurring in irregular sprays and subparallel groups. Chenowethite is pale...

Due to the high solubility of uranyl sulfate and selenite minerals, the investigation involving the determination of the crystal structures and physical properties of these minerals is essential in actinide environmental chemistry for the simulation of uranium migration from uraninite deposits and nuclear waste repositories. However, the determinat...

IMA No. 2022-054 Pendevilleite-(Y) Mg2Y3Al(UO2)2(CO3)7(OH)6(H2O)16 Pnv-Y Kamoto East Cu-Co deposit, Kolwezi mining district, Lualaba, Democratic Republic of the Congo (10°43’08.8” S, 25°25’04.7” E) Jakub Plášil*, Gwladys Steciuk, Radek Škoda, Simon Philippo and Mael Guennou *E-mail: plasil@fzu.cz New structure type Triclinic: P�1; structure determi...

Grandviewite is redefined on the basis of a reinvestigation of the holotype specimen from the Grandview mine, Arizona, USA, and additional specimens found in the Restauradora vein at the Capillitas mine, northwestern Argentina. Grandviewite from the Capillitas mine forms globular masses up to a couple of millimetres in diameter, formed by very thin...

The new mineral scenicite (IMA2021-057), [(UO2)(H2O)2(SO4)]2·3H2O, was found in the Green Lizard, Giveaway-Simplot, Markey and Scenic mines, White Canyon district, San Juan County, Utah, USA, where it occurs as a secondary phase on granular quartz matrix in association with various combinations of deliensite, gypsum, natrozippeite, rietveldite and...

Through the combination of low-temperature hydrothermal synthesis and room-temperature evaporation, a synthetic phase similar in composition and crystal structure to the Earth’s most complex mineral, ewingite, was obtained. The crystal structures of both natural and synthetic compounds are based on supertetrahedral uranyl-carbonate nanoclusters tha...

Tolstykhite, ideally Au 3 S 4 Te 6 , is a new mineral from the Gaching ore occurrence of the Maletoyvayam deposit, Kamchatka peninsula, Russia. It occurs as individual anhedral grains up to 0.05 mm or as intergrowths with native Se, native Te and tripuhyite. Other associated minerals include calaverite, fischesserite, Cu–Te-rich ‘fahlores' [stibiog...

Uranotungstite is an uranyl-tungstate mineral that was until recently only partially characterized with a formula originally given as (Fe2+,Ba,Pb)(UO2)2(WO4)(OH)4·12H2O and an unknown crystal structure. This mineral has been reinvestigated by electron microprobe analysis coupled with 3D electron diffraction. According to the electron microprobe dat...

The new mineral amgaite was discovered at the Khokhoyskoe gold deposit, 120 km W of Aldan town, Aldanskiy District, Sakha Republic (Yakutia), Eastern Siberia, Russia. Amgaite forms fine-grained colloform aggregates up to 0.05 mm across, and is often intimately intergrown with avicennite, unidentified carbonates and antimonates of Tl. Other associat...

The new mineral ferroberaunite, Fe2+Fe3+5(PO4)4(OH)5·6H2O (IMA 2021-36; symbol: Fbru), occurs in cavities of limonite iron ore from the Gravel Hill mine, Perranzabuloe, Cornwall, England, United Kingdom. Its flattened prismatic crystals up to 400 μm long are dark green to olive green, transparent to translucent, with a vitreous lustre, pearly on cl...

Gurzhiite, ideally Al(UO2)(SO4)2F·10H2O, is a new uranyl sulfate mineral from the Bykogorskoe U deposit, Northern Caucasus, Russia. It occurs as fine-grained aggregates forming veinlets up to 50 cm long in cracks of the brecciated rock. Gurzhiite aggregates are composed of small bladed crystals up to 0.1 mm across. Associated minerals include khade...

Nitscheite (IMA2020-078), (NH4)2[(UO2)2(SO4)3(H2O)2]·3H2O, is a new mineral species from the Green Lizard mine, Red Canyon, San Juan County, Utah, U.S.A. It is a secondary phase found in association with chinleite-(Y), gypsum, pyrite, and Co-rich rietveldite. Nitscheite occurs in subparallel and divergent intergrowths of yellow prisms, up to about...

Gungerite, TlAs5Sb4S13, is a new mineral from the Vorontsovskoye gold deposit in Northern Urals. It occurs in limestone breccias composed of calcite and dolomite, and cemented by orpiment, pyrite, realgar, stibnite, and minor baryte and quartz. It belongs to the latest phases among sulfosalts (chiefly Tl–As–Sb ones) present in the ore. The empirica...

Michalskiite (IMA2019-162), Cu2+Mg3Fe3+3.33(VO4)6, is a new mineral found on specimens from the dump of the Lichtenberg open pit, Ronneburg uranium mining district, Thuringia, Germany. It is a secondary mineral occurring with arcanite, epsomite, hematite and syngenite on matrix consisting of fine-grained quartz, K-feldspar and mica. It forms striat...

Weathering of ore minerals proceeds through initial transient products to many crystalline secondary minerals. However, the initial products are usually poorly characterized or overlooked because of their extremely small particle size, poor crystallinity, and chemical variability. Here, we document the strength of the precession-assisted three-dime...

Re-investigation of the type material of beraunite from the Hrbek Mine, Svatá Dobrotivá, Czech Republic, proved the identity of beraunite and eleonorite. Based on this study, the mineral eleonorite was discredited, and the ideal formula of beraunite was redefined from Fe2+Fe53+(PO4)4(OH)5 ⋅ 6H2O to Fe63+(PO4)4O(OH)4 ⋅ 6H2O. Beraunite from Hrbek Min...

The Vorontsovskoe gold deposit (Northern Urals) is unique in both Russia and the world because of the diverse and original Tl–Hg–Mn–As–Sb–S mineralization. Based on the available literature and our data, we present a list of 210 minerals found at this deposit. Eight of them are new minerals discovered by the authors: vorontsovite, ferrovorontsovite...

Gachingite, Au(Te 1– x Se x ), 0.2 ≈ x ≤ 0.5, is a new mineral discovered in the Gaching ore occurrence of the Maletoyvayam epithermal deposit, Kamchatka, Russia. Gachingite forms individual droplet-like grains of sizes from 2 to 10 μm included in native gold (Au–Ag), associated with calaverite, maletoyvayamite, watanabeite and Au–Sb oxides. The ag...

A synthetic analogue of the mineral natroboltwoodite was obtained unprecedently during a dissolution experiment with the mineral yttrialite-(Y), at a temperature of 200 °C, pressure ∼1.5 MPa, and strongly alkaline conditions. Natroboltwoodite formed along with analcime and aegirine. Single crystals of natroboltwoodite obtained allowed us to reveal...

Particularly interesting chemical variability in the U 4+ phosphate mineral vyacheslavite from Menzenschwand (Germany) has been discovered and investigated by means of electron-diffraction and micro-chemical methods. Suggested variability comprises namely the elevated contents of calcium and rare-earth elements (REEs). Based on the crystal structur...

The new mineral paramarkeyite (IMA2020–024), Ca2(UO2)(CO3)3·5H2O, was found in the Markey mine, San Juan County, Utah, USA, where it occurs as a secondary phase on gypsum-coated asphaltum in association with andersonite, calcite, gypsum and natromarkeyite. Paramarkeyite crystals are transparent, pale green-yellow, striated tablets, up to 0.11 mm ac...

Sluzhenikinite, Pd15(Sb7–xSnx) with 3 ≤ x ≤ 4, is a new mineral discovered in the pegmatoidal galena–chalcopyrite massive ore from the Oktyabrsk mine, Oktyabrsk deposit of the Noril`sk deposits, Russia. Sluzhenikinite forms euhedral elongate lamellar crystals (100–150 μm long and 10–50 μm wide) associated with Au–Ag alloy, insizwaite and myrmekitic...

In this work, the structures of chemically related uranyl-oxide minerals agrinierite and rameauite have been revisited and some corrections to the available structure data are provided. Both structures were found to be twinned. The two minerals are chemically similar, and though their structures differ considerably, their unit-cell metrics are simi...

Ferroberaunite IMA No. 2021-036 Chemical formula (ideal formula): Fe2+Fe3+5(PO4)4(OH)5⋅6H2O Mineral symbol: Fbru Type locality: Gravel Hill Mine, Perranzabuloe, Cornwall, England, United Kingdom Relationship to other minerals: The Fe2+ analogue of zincoberaunite Crystal system, Space group: Monoclinic: C2/c; structure determined Unit-cel...

This is a fnal paper in a series of publications devoted to the mineralogy of the Vorontsovskoe gold deposit in the Northern Urals. The article reports on oxygen compounds (oxyhalides, oxides, hydroxides, carbonates, sulfates, tungstates, phosphates, arsenates and silicates) of the Vorontsovskoe deposit, their chemical composition and, for selected...

The crystal structure of Tl 2.36 Sb 5.98 As 4.59 S 17 , the lead-free endmember of the chabournéite homeotypic group, from the Tl-As-Sb-rich gold deposit at Vorontsovskoye (the Urals, Russia) was determined and refined to R(obs) 0.099 for 9340 unique observed X-ray reflections. The triclinic unit-cell parameters determined from single-crystal data...

Auerbakhite (IMA 2020-047), MnTl2As2S5 , is a new sulfosalt from the Vorontsovskoe gold deposit, Sverdlovsk Ob-last', Northern Urals, Russia. The new mineral occurs in limestone breccias composed of calcite, dolomite, baryte, clinochlore, fluorapatite and quartz, and cemented by major realgar, orpiment and pyrite. Other minerals directly associatin...

The new sulfate mineral ferroefremovite, ideally (NH4)2Fe2+2(SO4)3, was discovered at the “Bocca Grande” fumarole, Solfatara di Pozzuoli, Flegrean Volcanic Complex, Naples Province, Campania, Italy. Associated minerals are adranosite, adranosite-(Fe), godovikovite, huizingite-(Al), mascagnite, and opal. Ferroefremovite forms cubic crystals up to 0....

This paper continues a series of publications devoted to the mineralogy of the Vorontsovskoe gold deposit in the Northern Urals (Kasatkin et al., 2020, 2021). The article reports on sulfosalts of the deposit, their chemical compositions, as well as unit-cell parameters, optical properties and Raman spectra of some minerals. For eight new mineral sp...

Dobšináite, ideally Ca 2 Ca(AsO 4) 2 ·2H 2 O, is a new supergene mineral from the Dobšiná deposit, Slovak Republic, associated with phaunouxite, picropharmacolite, erythrite-hörnesite, gypsum and aragonite. It forms white to pink clusters or polycrystalline aggregates up to 1-4 mm in size consisting of densely intergrown, slightly rounded thin tabu...

Uranyl carbonates are one of the largest groups of secondary uranium(VI)-bearing natural phases being represented by 40 minerals approved by the International Mineralogical Association, overtaken only by uranyl phosphates and uranyl sulfates. Uranyl carbonate phases form during the direct alteration of primary U ores on contact with groundwaters en...

The new mineral uranoclite (IMA2020-074), (UO2)2(OH)2Cl2(H2O)4, was found in the Blue Lizard mine, San Juan County, Utah, USA, where it occurs as tightly intergrown aggregates of irregular yellow crystals in a secondary assemblage with gypsum. The streak is very pale yellow and the fluorescence is bright green-white under 405 nm ultraviolet light....

Revisiting the structure of uranyl arsenate mineral hügelite provided some corrections to the available structural data. The previous twinning model (by reticular merohedry) in hügelite has been corrected. Twinning of the monoclinic unit cell [a = 7.0189 (7) Å, b = 17.1374 (10) Å, c = 8.1310 (10) Å and β = 108.904 (10)°], which can be expressed as...

The paper continues a series of publications devoted to the mineralogy of the Vorontsovskoe gold deposit in the Northern Urals (Kasatkin et al., 2020). The paper reports on native elements, sulfdes, arsenides and tellurides discovered at the deposit, their chemical compositions, as well as unitcell parameters and optical properties of some minerals...

The new mineral grimmite, NiCo2S4, was found in siderite–sphalerite gangue at the dump of shaft no. 9, one of the mines in the abandoned Příbram uranium and base-metal district, central Bohemia, Czech Republic. The new mineral occurs as rare idiomorphic to hypidiomorphic grains up to 200 µm × 70 µm in size or veinlet aggregates. In reflected light,...

Krupičkaite, ideally Cu6[AsO3(OH)]6·8H2O, is a new supergene mineral from the Rovnost I shaft in Jáchymov, Czech Republic. It forms aggregates of pale greenish-blue color and grows along with supergene minerals crystallizing on the strongly altered relics of massive tennantite, Bi-rich tennantite, galena, chalcopyrite, bornite, and chalcocite with...

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, gersdorf...

Seaborgite (IMA2019-087), LiNa6K2(UO2)(SO4)5(SO3OH)(H2O), is a new mineral species from the Blue Lizard mine, Red Canyon, San Juan County, Utah, U.S.A. It is a secondary phase found on gypsum in association with copiapite, ferrinatrite, ivsite, metavoltine, and römerite. Seaborgite occurs in sprays of light-yellow, long flattened prisms or blades,...

Kaatialaite mineral Fe[AsO2(OH)2]5H2O from Jáchymov, Czech Republic forms white aggregates of needle-shaped crystals with micrometric size. Its structure at ambient temperature has already been reported but hydrogen atoms could not be identified from single-crystal X-ray diffraction. An analysis using 3D electron diffraction at low temperature brin...

Panskyite, Pd 9 Ag 2 Pb 2 S 4 , 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 inclusio...

This work is the frst paper in a series of publications dedicated to mineralogy of the Vorontsovskoe gold deposit in the Northern Urals. The deposit is unique for both Russia and world with regard to the diversity and originality of Tl–Hg–Mn–As–Sb–S mineralization. Based on available literature and our data, we compiled an exhaustive list of 209 mi...

A rare supergene uranyl phosphate mineral, phurcalite, was found on a few specimens originating from the dump material of the Eduard shaft, the Jáchymov ore district, Czech Republic. Phurcalite forms yellow to yellowish-orange perfect prismatic crystals, reaching up to 3 - 4 mm in cavities of vuggy quartz-dominated gangue. Phurcalite was found in t...

The crystal structure of the rare supergene Pb2+-containing uranyl-oxide mineral wölsendorfite has been revisited employing the single-crystal X-ray diffraction. The new structure refinement provided deeper insight into the complex structure of this mineral, revealing additional H2O sites in the interlayer complex and confirming the entrance of the...

The new sulfosalt chukotkaite, ideally AgPb7Sb5S15, was discovered in the valley of the Levyi Vulvyveem river, Amguema river basin, Iultin District, Eastern Chukotka, Chukotka Autonomous Okrug, North-Eastern region, Russia. The new mineral forms anhedral grains up to 0.4 × 0.5 mm intergrown with pyrrhotite, sphalerite, galena, stannite, quartz, and...

The new mineral percleveite-(La) (IMA2019–037), ideally La 2 Si 2 O 7 , 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), f...

The underground spaces of the former mines in Jáchymov, Czech Republic and Rotgülden, Austria house diverse assemblages of secondary minerals, mostly arsenates. The formation conditions and processes involved with the secondary minerals were deciphered using field observations, sampling of both solids and co-existing aqueous solutions, calorimetric...

The new mineral pošepnýite was found in the mine dump of the shaft No. 16 Háje, one of the mines in the Příbram uranium and base-metal district, central Bohemia, Czech Republic. Pošepnýite is associated with příbramite, dzhar-kenite, ferroselite, hakite-(Hg), tetrahedrite-(Zn), antimonselite and uraninite in a calcite-dominant gangue. The new miner...

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 crystallized from As–, Cu– and Mn–rich fluids and it is associated with braunite, copper, cuprite, rhodochrosite and strashimirite. Monteneroite occurs as ligh...

The research involving the crystal structures and properties of uranyl carbonate minerals is essential in actinide environmental chemistry due to the fundamental role played by these minerals in the migration of actinides from uranium deposits and nuclear waste repositories and in the investigation of accidental site contaminations. In this work, t...

The new minerals natromarkeyite, Na 2 Ca 8 (UO 2) 4 (CO 3) 13 (H 2 O) 24 ⋅3H 2 O (IMA2018-152) and pseudomarkeyite, Ca 8 (UO 2) 4 (CO 3) 12 (H 2 O) 18 ⋅3H 2 O (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...

Fulbrightite (IMA2019-032), Ca(VO) 2 (AsO 4) 2 Á4H 2 O, is a new mineral from the Packrat mine, near Gateway, Mesa County, Colorado, USA, and from the Rovnost mine, Jáchymov, Czech Republic. It is a low-temperature secondary phase. The mineral most typically occurs in shades of light green and forms rosettes of roughly square (pseudotetragonal) pla...

The determination of the full crystal structure of the uranyl sulfate mineral uranopilite, (UO2)6(SO4)O2(OH)6.14H2O, including the positions of the hydrogen atoms within the corresponding unit cell, has not been feasible to date due to the poor quality of its X-ray diffraction pattern. In this paper, the complete crystal structure of uranopilite is...

The determination of the full crystal structure of the uranyl sulfate mineral uranopilite, (UO2 )6 (SO4)O2(OH)6·14 H2O, including the positions of the hydrogen atoms within the corresponding unit cell, has not been feasible up to date due to the poor quality of its X-ray diffraction pattern. In this paper, the complete crystal structure of uranopil...