Fabrice Dal Bo

University of Liège | ulg · Department of Geology

Zinconigerite-2N1S ZnSn2Al12O22(OH)2 and zinconigerite-6N6S Zn3Sn2Al16O30(OH)2 are two new minerals with different numbers and ratios of nolanite (N) and spinel (S) modules. Both phases have been discovered in the Xianghualing skarn, Hunan Province, China. Zinconigerite-2N1S (zn-2N1S) and zinconigerite-6N6S (zn-6N6S) are named for their chemical co...

A carbonate-bearing, fluorine-overcompensated fluorapatite (F = 4.42 wt.% as compared with 3.77 wt.% F in the Ca5(PO4)3F end-member), was identified in forsterite-bearing skarns from Valea Rea (N 46°39′48″, E 22°36′43″), located near the contact of the granodiorite laccolith from Budureasa, of Upper Cretaceous Age, with Anisian dolostones. The chem...

The new mineral, illoqite-(Ce), with the ideal formula Na2NaBaCeZnSi6O17, has been discovered in the Taseq Slope, Ilímaussaq Alkaline Complex, Southern Greenland. Illoqite-(Ce) occurs in a hyperalkaline ussingite vein closely related to one of the largest ussingite veins in the Ilímaussaq complex. The associated minerals are aegirine, arfvedsonite,...

A nomenclature and classification scheme for wöhlerite group minerals has been established. The general formula of minerals belonging to this group is given by X8(Si2O7)2W4, where X = Na+, Ca2+, Mn2+, Ti4+, Zr4+ and Nb5+; and W = F- and O2-. In addition, they may incorporate significant amounts of Mg2+, Fe2+, Y3+ and REE3+, where REE are the lantha...

Des filons plombifères à gangue baritée sont observés dans la région de Martelange et notamment à Wisembach dans la formation de Villé, une formation du Dévonien inférieur (Praguien) connue pour être traversée par de nombreux filons plombifères. La présence de barite dans ces filons est cependant atypique pour l’Ardenne belge, et cette observation...

The new beudantite-group mineral oberwolfachite, ideally SrFe ³⁺ 3 (AsO 4 )(SO 4 )(OH) 6 , was discovered in two localities: Clara mine, Oberwolfach, Schwarzwald, Baden-Württemberg, Germany (holotype) and Monterniers mine, Lantignié, Rhône, Auvergne-Rhône-Alpes, France (cotype). The associated minerals are quartz, baryte, hematite, illite, goethite...

The crystal chemistries of five samples of minerals belonging to the fillowite group were structurally investigated: (A) fillowite from the Buranga pegmatite, Rwanda; (B) fillowite from the Kabira pegmatite, Uganda; (C) johnsomervilleite from Loch Quoich, Scotland; (D) johnsomervilleite from the Malpensata pegmatite, Italy; and (E) chladniite from...

A nomenclature scheme has been set up for the nordite supergroup of minerals, which have the general formula A 2 BXYZT 6 O 17 and where A = Na; B = Na, Ca; X = Sr, Ca, Ba; Y = REE , Sr; Z = Zn, Fe, Mn, Mg and T = Si. The nordite supergroup includes nordite-(La), nordite-(Ce), ferronordite-(La), ferronordite-(Ce) and manganonordite-(Ce), as well as...

Two uranyl vanadate heteropolyoxometalates (h-POMs) have been synthesized by ionothermal methods using the ionic liquid 1-ethyl-3-methylimidazolium diethyl phosphate (EMIm-Et2PO4). The hybrid actinide-transition metal shell structures have cores of (UO2)8(V6O22) and (UO2)6(V3O12), which we designate as {U 8 V 6 } and {U 6 V 3 } , respecti...

Limousinite, ideally BaCa[Be4P4O16]·6H2O, is a new beryllophosphate mineral discovered in the Vilatte-Haute pegmatite, Chanteloube near Razès, Limousin, Haute-Vienne, France. The new mineral is intimately associated with microcrystalline pale brown greifensteinite, black amorphous vitreous Mn-oxyhydroxide, triplite, and quartz. It forms isolated, p...

Jeankempite, Ca 5 (AsO 4) 2 (AsO 3 OH) 2 (H 2 O) 7 , is a new mineral species (IMA 2018-090) discovered amongst coatings of arsenate minerals on oxidized 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 in width and is visually in...

A shallow-level monzodioritic to quartz-monzodioritic pluton of the Upper Cretaceous age caused contact metamorphism of Tithonic-Kimmeridgian reef limestones at Măgureaua Vaţei (Metaliferi Massif, Apuseni Mountains, Romania). The preserved peak metamorphic assemblage includes gehlenite (Ak 33.64-38.13), monticellite, wollastonite-2M, Ti-poor calcic...

Halilsarpite, [Mg(H2O)6][CaAs23+(Fe2.673+Mo0.336+)(AsO4)2O7], is a new secondary mixed arsenate/arsenite mineral from the Oumlil mine, Bou Azzer district, Morocco. It forms lemon-yellow spherules, about 0.1 mm in diameter, composed of platelets, some tens of micrometres in diameter but only 1–2 µm thick. The platelets are flattened on {100} and exh...

Over the past decade, an average of well over 100 new minerals per year have been discovered and approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association. Exploration of abandoned mines and re-investigation of samples from classic localities have allowed mineralogists to discover mor...

The ionic liquid 1-ethyl-3-methylimidazolium diethyl phosphate (EMIM-Et⁠2PO⁠4) was used in the synthesis of four new hybrid organic-inorganic uranyl phosphates. The structure of (UO⁠2)[PO⁠2(OC⁠2H⁠5)⁠2]⁠2 (1) is triclinic, P-1, a=5.374(3) Å, b=7.674(4) Å, c=11.132(6) Å, α=105.333(6)°, β=90.562(6)°, γ=98.269(6)°, Z=4. The structure of (C⁠6N⁠2H⁠11){(U...

An aromatic ligand was introduced into the synthesis of a uranyl peroxide polyoxometalate (POM) formulated as K32(UO2)19(O2)26(OH)2(C6H4P2O6)4⋅65 H2O that consists of a unique “open oyster” shaped structure (U19) with intramolecular H-bonds. In the solid state, K-π and π-π interactions, as well as K-O bonds enable the formation of a supramolecular...

Uranyl vanadate compounds with divalent cations, M(UO2)(V2O7) (M = Ca, Sr) and Sr3(UO2)(V2O7)2, were synthesized by flux crystal growth, and their crystal structures were solved using single-crystal X-ray diffraction data. Ca(UO2)V2O7 and Sr(UO2)V2O7 were synthesized from reactants with molar ratios M:U:V of 1:1:2 and identical heating conditions,...

Five novel microporous uranyl germanates, Cs[(UO2)2(HGe2O7)] (1), Co2[(UO2)8(HGe2O7)4](H2O)6 (2), Ba2[(UO2)8(HGe2O7)4](H2O)3 (3), K4[(UO2)8(HGe2O7)4](H2O)2 (4), and Rb4[(UO2)8(HGe2O7)4](H2O)2 (5), have been synthesized under hydrothermal conditions. Single-crystal X-ray analyses indicate that 1 has an orthorhombic structure, space group Cmcm, while...

A novel hydrated magnesium uranyl germanate, Mg[(UO2)2(Ge2O6(OH)2)]∙(H2O)4.4, has been synthesized under hydrothermal conditions at 200 °C. The orthorhombic unit-cell parameters are a = 10.829(6), b = 7.625(4), c = 16.888(10) Å, V = 1394.5(1) Å3, space group Cmcm, Z = 4. The crystal structure is based on β-U3O8-type sheets of corner- and edge-shari...

Paddlewheelite, MgCa5Cu2[(UO2)(CO3)3]4�33H2O, is a new uranyl carbonate mineral found underground in the Svornost mine, Jáchymov District, Bohemia, Czech Republic, where it occurs as a secondary oxidation product of uraninite. The conditions leading to its crystallization are complex, likely requiring concomitant dissolution of uraninite, calcite,...

A novel anhydrous neptunyl(V) compound, Rb2[Ca(NpO2)2(PO4)2], was obtained by hydrothermal synthesis. It crystallizes in the orthorhombic space group Pbca with the unit-cell parameters a = 12.972(2), b = 13.213(3), c = 7.090(3) Å, V = 1215.3(6) Å3, Z = 4. The crystal structure is based on sheets of neptunyl and phosphate polyhedra representing a ne...

The Rabejac uranium deposit that is located in the Lodève region, France, is the type locality for three uranyl minerals species (fontanite, seelite, and rabejacite). In addition, this deposit shows an extraordinary supergene uranyl mineralization characterized by the presence of many rare secondary uranyl species. In the present study, a mineralog...

The bismuth(III) oxophosphate Bi3(PO4)O3 was obtained by hydrothermal synthesis. The unit cell has a = 5.6840(6) Å, b = 7.0334(7) Å, c = 9.1578(9) Å, α = 78.958(2)°, β = 77.858(2)°, γ = 68.992(2)°, V = 331.41(6) Å3, space group P1̅, and Z = 2. The crystal chemical formula that reflects the presence of oxo-centered tetrahedra and triangles is 2D[OII...

Plumbopharmacosiderite, Pb0.5Fe³⁺4(AsO4)3(OH)4·5H2O, is a new hydrated and hydroxylated arsenate of Fe³⁺ and Pb belonging to the pharmacosiderite group, pharmacosiderite supergroup of minerals. It was found at the Monte Falò Pb-Zn mine near the village of Coiromonte in the Armeno municipality, Novara province, Italy. The mineral occurs on the surfa...

The first uranyl beryllophosphate, [(UO2)2{Be(H2O)2(PO4)2}]∙(H2O), has been synthesized under hydrothermal conditions at 200°C. The monoclinic unit-cell parameters are: a = 9.3361(1), b = 8.8545(4), c = 9.6583(4) Å, β = 93.227(4)°, V = 797.15(6) Å3, space group P2/n, Z = 2. The crystal structure has been solved by direct methods and refined to fina...

Cet article présente les concepts basiques de la minéralogie de l’uranium. Après un bref exposé sur la cristallochimie de cet élément, quelques espèces de minéraux uranifères sont décrites afin de mettre en évidence leur complexité structurale. L’étude de ces phases est de première importance pour les problématiques liées à la gestion des déchets n...

Wilancookite, ideally (Ba, K, Na)8(Ba, Li, □)6Be24P24O96 32H2O, is a new mineral species from the Lavra Ponte do Piauí complex granitic pegmatite, Minas Gerais, Brazil. It occurs as tiny dodecahedral {1 1 0} crystals, deposited on moraesite fibres. Associated primary minerals are albite, montebrasite, Li-bearing micas, cassiterite, elbaite and quar...

Mengxianminite, ideally Ca2Sn2Mg3Al8[(BO3)(BeO4)O6]2, is a new borate mineral from Xianghualing skam, Hunan Province, southern China. It occurs in the hsianghualite vein of Xianghualing skarn, associated with fluorite, phlogopite, hsianghualite, magnetite, dravite, magnesiotaaffeite-2N'2S, and calcite. Mengxianminite forms subhedral to euhedral gre...

The crystal structure of phuralumite, Al2[(UO2)3(PO4)2O(OH)](OH)3(H2O)9, from the Kobokobo pegmatite (Kivu, Democratic Republic of Congo), was refined from single crystal X-ray diffraction data. Four samples have been investigated in this study, and the crystal structure was refined to R1 = 0.0566, 0.0544, 0.0661 and 0.0353, for 5739, 5953, 6007 an...

The crystal structure of furongite, Al4[(UO2)4(PO4)6](OH)2(H2O)19.5, from the Kobokobo pegmatite, Kivu, Democratic Republic of Congo, was solved for the first time. Furongite is triclinic, the space group P&1macr;, Z=2, a = 12.1685(8), b = 14.1579(6), c = 17.7884(6) , α = 79.822(3), β = 77.637(4), γ = 67.293(2)°, and V = 2746.2(2)3. The crystal str...

In order to assess the stability of the primary triphylite sarcopside assemblage, we performed hydrothermal experiments between 400 and 700 8C (Ni/NiO oxygen fugacity buffer, P=1 kbar), starting from the Li(Fe²⁺ 2.5-xMn²⁺ x)(PO4)2 (x=0.0, 0.5, 1.0) compositions, which represent the ideal compositions of triphylite+sarcopside assemblages in which bo...

Arrojadite-(BaNa), BaNa³(na,ca)Fe²⁺ 13al(PO4)11(PO3OH)(OH2, is the Na-, Ba-rich member of the arrojadite group. This primary phosphate was found at the Luna albite pegmatite, Dorio, Lecco province, Italy where it occurs associated with fluorapatite in the blocky-albite unit of the pegmatite. This new phosphate forms greenish or yellowish translucen...

The crystal structures of two autunite-group minerals have been solved recently. The crystal structure of bassetite, Fe2+[(UO2)(PO4)]2(H2O)10, from the type locality in Cornwall, United Kingdom (Basset Mines) was solved for the first time. Bassetite is monoclinic, space group P21/n, a = 6.961(1), b = 20.039(2), c = 6.974(1) Å and β = 90.46(1)°. The...

Minjiangite, ideally BaBe2(PO4)2, is a new mineral species which has been found in the Nanping No. 31 pegmatite, Fujian Province, southeastern China. It occurs in the fractures of montebrasite from pegmatite zone IV, and is associated with quartz, muscovite, hydroxylapatite and palermoite. Minjiangite forms subhedral to euhedral white crystals from...

Wollastonite from three occurrences of high-temperature skarns in Romania: Măgureaua Vaţei (MV), Cornet Hill (CH) and Oraviţa (Or), was investigated from crystal-chemical and crystallographical point of view, in order to assay its use as industrial mineral. In all cases, wollastonite-2M occurs in gehlenite-bearing skarns within the contact between...

Abstract: The crystal structure of the natural aluminium uranyl arsenate hydrate arsenuranospathite, ideally Al[(UO2)(AsO4)]2F(H2O)20, from the Rabejac deposit, Lode`ve, France, was solved for the first time. Arsenuranospathite is orthorhombic, space group Pnn2, Z¼ 2, a¼ 29.9262(7), b ¼ 7.1323(1), c ¼ 7.1864(1)A° , and V ¼ 1533.9(1)A ° 3. The cryst...

Four beryllophosphates with general formula M2+Be2P2O8 (M2+ = Ca, Sr, Pb, Ba) have been synthesized under hydrothermal conditions at 200 °C. Their crystal structures were solved by direct methods and refined by full-matrix least-squares techniques on the basis of F2 for all unique reflections to agreement indices R1 of 2.3, 4.8, 1.5, and 2.1%, resp...

The Jocão pegmatite (or Cigana) is located in the well-known Eastern Brazilian Pegmatitic Province (EBPP), Minas Gerais, Brazil. According to their macroscopic textures, three different kinds of phosphate mineral masses were collected from the dumps of the pegmatite: association I is composed of dendritic triphylite, forming intergrowths with silic...

In order to assess the stability of Fe-rich alluaudites in pegmatites, we performed hydrothermal experiments between 400 and 700 °C (1 kbar), in the Na-Fe2+-Fe3+ (+PO4) ternary system. These experiments produced several new phosphate minerals, among which was Na2Fe3+(HPO4)(PO4)·H2O [a 15.5004(8), b 7.1465(5), c 29.239(2)Å, V 3238.9(3)Å3, Pnma], whi...

Strontiohurlbutite, ideally SrBe2(PO4)2, is a new member of hurlbutite group discovered in the Nanping No. 31 pegmatite, Fujian province, southeastern China. Crystals are mainly found in zones I, II, and IV; they are platy, subhedral-to-anhedral, with a length from 5 mm to 1.5 mm. Associated minerals mainly include quartz, muscovite, beryl, hurlbut...

Two new mixed-valence iron phosphates, namely heptairon pentaphosphate hydrogen phosphate, Fe(6.67)(PO(4))(5.35)(HPO(4))(0.65), and heptairon tetraphosphate bis(hydrogen phosphate), Fe(6.23)(PO(4))(4.45)(HPO(4))(1.55), have been synthesized hydrothermally at 973 K and 0.1 GPa. The structures are similar to that of Fe(II)(3)Fe(III)(4)(PO(4))(6) and...

This paper reports a new partially oxidized triphylite-type phosphate (lithium iron phosphate), which has been synthesized hydrothermally at 973 K and 0.1 GPa. The structure is similar to that of natural triphylite, LiFe(PO 4 ), and is characterized by two chains of edge-sharing octahedra parallel to the b axis. The weakly distorted M 1 octahedra c...

This paper reports a new partially oxidized triphylite-type phosphate (lithium iron phosphate), which has been synthesized hydrothermally at 973 K and 0.1 GPa. The structure is similar to that of natural triphylite, LiFe(PO4), and is characterized by two chains of edge-sharing octahedra parallel to the b axis. The weakly distorted M1 octahedra cont...

This paper reports a new partially oxidized triphylite-type phosphate (lithium iron phosphate), which has been synthesized hydrothermally at 973 K and 0.1 GPa. The structure is similar to that of natural triphylite, LiFe(PO(4)), and is characterized by two chains of edge-sharing octahedra parallel to the b axis. The weakly distorted M1 octahedra co...