Adamantine Luster Research Articles

Langhofite, Pb2(OH)[WO4(OH)], a new mineral from Långban, Sweden

AbstractLanghofite, ideally Pb2(OH)[WO4(OH)], is a new mineral from the Långban mine, Värmland, Sweden. The mineral and its name were approved by the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (IMA2019-005). It occurs in a small vug in hematite–pyroxene skarn associated with calcite, baryte, fluorapatite, mimetite and minor sulfide minerals. Langhofite is triclinic, space group P$\bar{1}$, and unit-cell parameters a = 6.6154(1) Å, b = 7.0766(1) Å, c = 7.3296(1) Å, α = 118.175(2)°, β = 94.451(1)°, γ = 101.146(1)° and V = 291.06(1) Å3 for Z = 2. The seven strongest Bragg peaks from powder X-ray diffractometry are [dobs, Å (I)(hkl)]: 6.04(24)(010), 3.26(22)(11$\bar{2}$), 3.181(19)(200), 3.079(24)(1$\bar{1}$2), 3.016(100)(020), 2.054(20)(3$\bar{1}$1) and 2.050(18)(13$\bar{2}$). Langhofite occurs as euhedral crystals up to 4 mm, elongated along the a axis, with lengthwise striation. Mohs hardness is ca. 2½, based on VHN25 data obtained in the range 130–192. The mineral is brittle, with perfect {010} and {100} cleavages. The calculated density based on the ideal formula is 7.95(1) g⋅cm–3. Langhofite is colourless to white (non-pleochroic) and transparent, with a white streak and adamantine lustre. Reflectance curves show normal dispersion, with maximum values 15.7–13.4% within 400–700 nm. Electron microprobe analyses yield only the metals Pb and W above the detection level. The presence of OH-groups is demonstrated with vibration spectroscopy, from band maxima present at ~3470 and 3330 cm–1. A distinct Raman peak at ca. 862 cm–1 is related to symmetric W–oxygen stretching vibrations. The crystal structure is novel and was refined to R = 1.6%. It contains [W2O8(OH)2]6– edge-sharing dimers (with highly distorted WO6-octahedra) forming chains along [101] with [(OH)2Pb4]6+ dimers formed by (OH)Pb3 triangles. Chains configure (010) layers linked along [010] by long and weak Pb–O bonds, thus explaining the observed perfect cleavage on {010}. The mineral is named for curator Jörgen Langhof (b. 1965), who collected the discovery sample.

A new mineral borisenkoite, Cu3[(V,As)O4]2, and the isomorphous series borisenkoite–lammerite-β in fumarolic exhalations of the Tolbachik volcano, Kamchatka, Russia

The new mineral borisenkoite Cu3[(V,As)O4]2 was found in sublimates of the Yadovitaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. Associated minerals are sanidine, hematite, lammerite, lammerite-β, bradaczekite, zincobradaczekite, mcbirneyite, pseudolyonsite, lyonsite, starovaite, tenorite, rutile, tripuhyite, pseudobrookite, piypite, langbeinite, calciolangbeinite, aphthitalite, alumoklyuchevskite, palmierite, cupromolybdite, and corundum. Borisenkoite forms (1) prismatic crystals (up to 0.04 × 0.04 × 0.10 mm3) usually combined in clusters up to 0.4 mm and (2) rims up to 0.05 mm in width around lammerite. Borisenkoite is red-brown, golden-brown or brown, with strong greasy to adamantine lustre. Dcalc is 4.69 g·cm−3. Chemical composition (wt.%, electron-microprobe) is: CuO 53.25, ZnO 1.13, Fe2O3 0.16, P2O5 0.05, V2O5 25.06, As2O5 20.44, total 100.07. The empirical formula, based on 8 O apfu, is: (Cu2.94Zn0.06Fe0.01)Σ3.01(V1.21As0.78)Σ1.99O8. Borisenkoite is monoclinic, P21/c, a 6.3779(7), b 8.6021(9), c 11.3597(11) A, β 92.013(8)o, V 622.84(11) A3 and Z = 4. The strongest reflections in the powder XRD pattern [d,A(I)(hkl)] are: 4.309(48)(− 102, 020), 3.424(40)(022, − 121), 2.994(48)(113, 210), 2.917(50)(− 211), 2.830(100)(004), 2.782(92)(031) and 2.568(38)(123). The crystal structure was solved from single-crystal XRD data and refined to R = 0.0654. Borisenkoite is isotypic with lammerite-β. They form a limited solid-solution series extended from Cu3(AsO4)2 to Cu3(V1.5As0.5)O8, with gap between Cu3(As1.75V0.25)O8 and Cu3(As1.25V0.75)O8. The assumption that As5+ can stabilize borisenkoite structure is the reason to propose the simplified formula Cu3[(V,As)O4]2 avoiding the formal end-member formula Cu3(VO4)2. Borisenkoite is named in honour of the Russian geochemist, mineralogist, and geologist Leonid Fedorovich Borisenko (1922–2000).

Adding complexity to the garnet supergroup: monteneveite, Ca<sub>3</sub>Sb<sup>5+</sup><sub>2</sub>(Fe<sup>3+</sup><sub>2</sub>Fe<sup>2+</sup>)O<sub>12</sub>, a new mineral from the Monteneve mine, Bolzano Province, Italy

Abstract. Monteneveite, ideally Ca3Sb25+(Fe23+Fe2+)O12, is a new member of the garnet supergroup (IMA 2018-060). The mineral was discovered in a small specimen belonging to the Swedish Museum of Natural History coming from the now abandoned Monteneve Pb–Zn mine in Passiria Valley, Bolzano Province, Alto Adige (South Tyrol), Italy. The specimen consists of mainly magnetite, sphalerite, tetrahedrite-(Fe) and oxycalcioroméite. Monteneveite occurs as black, subhedral crystals with adamantine lustre. They are equidimensional and up to 400 µm in size, with a subconchoidal fracture. Monteneveite is opaque, grey in reflected light, and isotropic under crossed polars. Measured reflectance values (%) at the four COM wavelengths are 12.6 (470 nm), 12.0 (546 nm), 11.6 (589 nm) and 11.4 (650 nm). The Vickers hardness (VHN100) is 1141 kg mm−2, corresponding to H=6.5–7, and the calculated density is 4.72(1) g cm−3. A mean of 10 electron microprobe analyses gave (wt %) CaO 23.67, FeO 3.75, Fe2O3 29.54, Sb2O5 39.81, SnO2 2.22, ZnO 2.29, MgO 0.15, MnO 0.03 and CoO 0.03. The crystal chemical formula calculated on the basis of a total of eight cations and 12 anions, and taking into account the available structural and spectroscopic data, is (Ca2.97Mg0.03)Σ=3.00 (Sb1.735+Sn0.104+Fe0.173+)Σ=2.00(Fe2.433+Fe0.372+Zn0.20)Σ=3.00O12. The most significant chemical variations encountered in the sample are related to a substitution of the type YSn4++ZFe3+→YSb5++ZFe2+. Mössbauer data obtained at RT and 77 K indicate the presence of tetrahedrally coordinated Fe2+. Raman spectroscopy demonstrates that there is no measurable hydrogarnet component in monteneveite. The six strongest Bragg peaks in the powder X-ray diffraction pattern are [d (Å), I (%), (hkl)]: 4.45, 100, (220); 3.147, 60, (400); 2.814, 40, (420); 2.571, 80, (422); 1.993, 40, (620); 1.683, 60, (642). Monteneveite is cubic, space group Ia-3‾d, with a=12.6093(2) Å, V=2004.8(1) Å3, and Z=8. The crystal structure was refined up to R1=0.0197 for 305 reflections with Fo>4σ(Fo) and 19 parameters. Monteneveite is related to the other Ca-, Sb- and Fe-bearing, nominally Si-free members of the bitikleite group, but it differs in that it is the only known garnet species with mixed trivalent and divalent cations (2:1) at the tetrahedral Z site. Textural and mineralogical evidence suggests that monteneveite formed during peak metamorphism (at ca. 600 ∘C) during partial breakdown of tetrahedrite-(Fe) by reactions with carbonate, under relatively oxidizing conditions. The mineral is named after the type locality, the Monteneve (Schneeberg) mine.

Mauriziodiniite, NH4(As2O3)2I, the ammonium and iodine analogue of lucabindiite from the Torrecillas mine, Iquique Province, Chile

AbstractThe new mineral mauriziodiniite (IMA2019-036), NH4(As2O3)2I, was found at the Torrecillas mine, Iquique Province, Chile, where it is a secondary alteration phase associated with calcite, cuatrocapaite-(NH4), lavendulan, magnesiokoritnigite and torrecillasite on matrix consisting of native arsenic, arsenolite and pyrite. Mauriziodiniite occurs as hexagonal tablets up to ~300 μm in diameter. Crystals are colourless and transparent, with pearly to adamantine lustre and white streak. The Mohs hardness is ~1. Tablets are sectile and easily flexible, but not elastic. Fracture is curved, irregular and stepped. Cleavage is perfect on {001}. The calculated density is 3.916 g/cm3. Optically, mauriziodiniite is uniaxial (–) with ω = 2.07(calc) and ɛ = 1.770(5) (white light). The empirical formula, determined from electron microprobe analyses, is (NH4)0.94K0.03(As2O3)2I0.92Cl0.03. Mauriziodiniite is hexagonal, P6/mmm, a = 5.289(2), c = 9.317(2) Å, V = 225.68(18) Å3 and Z = 1. The structure, refined to R1 = 4.16% for 135 Io > 2σI reflections, contains three types of layers: (1) a planar neutral As2O3 (arsenite) sheet; (2) an NH4+ layer that links adjacent arsenite sheets via bonds to their O atoms; and (3) an I– layer that links adjacent arsenite sheets via bonds to their As atoms. The layer sequence is I–As2O3–NH4–As2O3–I. Mauriziodiniite is isostructural with lucabindiite and is structurally related to gajardoite, cuatrocapaite-(NH4), cuatrocapaite-(K) and torrecillasite.

Huenite, Cu4Mo3O12(OH)2, a New Copper-molybdenum Oxy-hydroxide Mineral from the San Samuel Mine, Carrera Pinto, Cachiyuyo De Llampos District, CopiapÓ Province, Atacama Region, Chile

Abstract Huenite, Cu4Mo3O12(OH)2, is a new copper and molybdenum oxy-hydroxide mineral found in the San Samuel Mine, Carrera Pinto, Cachiyuyo de Llampos district, Copiapó Province, Atacama Region, Chile. This new species forms flattened orthorhombic prisms up to 60–70 μm in size, weakly elongated along [001]. Huenite crystals were found on fractured surfaces of a quartz breccia, forming aggregates 1 mm in diameter in close association with lindgrenite, gypsum, dark grayish-brown tourmaline, and an unknown pale purple phase. The color is very dark reddish-brown, with a strong vitreous to adamantine luster. Its streak is pale reddish-brown to pinkish. The mineral is brittle with an irregular fracture and a Mohs hardness of 3.5–4 with a good cleavage on {010}. Its calculated density is 5.1 g/cm3. The calculated refractive index is 2.18. Huenite is non-fluorescent under 254 nm (short wave) and 366 nm (long wave) ultraviolet light. The empirical formula, calculated on the basis of 3 (Mo+S+Si) atoms per formula unit, is (Cu3.519Fe2+0.403)Σ3.922(Mo2.907S0.090Si0.003)Σ3.000O12·(OH)2.229, with H2O content calculated for a total of 100 wt.%. Huenite is trigonal, with space group P31/c and unit-cell parameters a = 7.653(5) Å, c = 9.411(6) Å, and V = 477.4(5) Å3 for Z = 2. The eight strongest measured powder X-ray diffraction lines are: [d in Å, (I/I0), (hkl)]: 2.974 (100) (112), 1.712 (59.8) (132), 3.810 (50.6) (110), 2.702 (41.2) (022), 2.497 (38.1) (120), 1.450 (37.2) (134), 6.786 (24.9) (010), and 5.374 (24.5) (011). The mineral, which has been approved by the CNMNC under number IMA 2015-122, is named in honor of Edgar Huen.

Gaildunningite, Ideally Hg2+3[NHg2+2]18(Cl,I)24, a New Mineral from the Clear Creek Mine, San Benito County, California, USA: Description and Crystal Structure

Gaildunningite, ideally Hg-3(2+)[NHg22+](18)(Cl,I)(24), is a new mineral from the Clear Creek mine, New Idria mining district, San Benito County, California, USA. It is orthorhombic, space group Amam, Z 1/4 4; a 26.381(6), b 45.590(10), c 6.6840(15) angstrom, V 8039(5) angstrom(3). Chemical analysis by electron microprobe gave Hg 76.87, I 12.55, Cl 3.79, Br 0.56, S 0.18 wt.%; N 2.45, O 0.28, and H 0.02 wt.% were derived from the crystal structure to give a total of 96.70 wt.%. The empirical formulae (calculated on the basis of 39.44 Hg with 18 N and OH added to give electroneutrality) is Hg39.442+N18[Cl11.00I10.18(OH)(1.81)Br0.73S0.58](Sigma 24.30) and the simplified formula is Hg-3(2+)[NHg22+](18)(Cl,I)(24). The seven strongest lines in the X-ray powder diffraction pattern [listed as d (angstrom), I, (hkl)] are as follows: 2.853, 100, (880, 0.16.0); 2.776, 100, (462, 5.14.0); 2.745, 100, (542); 5.717, 50, (440, 080); 5.965, 40, (131); 5.018, 40, (331); 1.673, 40, (004). Gaildunningite generally forms complex parallel intergrowths of fibrous to acicular crystals elongated along [001]. Acicular yellow to orange to darker orange-red crystals up to 0.1 mm long form matted nests lining vugs within white-grey quartz. Gaildunningite has a vitreous to adamantine luster, is transparent, and does not fluoresce under short-or long-wave ultraviolet light. Mohs hardness approximate to 3 and the calculated density is 8.22 g/cm(3). It is brittle with an uneven fracture and has very good cleavage on {100} and {010} and good cleavage on {001}; neither parting nor twinning was observed. It is grey in reflected light with possibly minor bireflectance but no reflectance pleochroism, and strong yellow-orange internal reflections are evident even in plane-polarized light. The Raman spectrum indicates the presence of Hg-N bonds in the structure. The crystal structure of gaildunningite is based on a well-ordered three-dimensional [NHg2](+) net of near-linear N-Hg-N groups, where each N3- is tetrahedrally coordinated by Hg2+. The net is comprised of two five-membered, three six-membered, one seven-membered, and one eight-membered rings of N-Hg-N groups. The interstitial part of the structure is significantly disordered and consists of (Hg2+) and (I-, Cl-, Br-, S2-, OH-) ions. A new bond-valence parameter has been derived for (Hg2+-N3-) bonds: R-o = 1.964 angstrom, b 1/4 0.37; this gives bond-valence sums at the N3- ions in accord with the valence-sum rule.Gaildunningite and unnamed CCUK-18 are the only (Hg-N-I)-bearing minerals discovered at Clear Creek to date and are closely associated; gaildunningite is the later of these two minerals and tends to grow on CCUK-18. They post-date the iodine-free nitride mosesite and the (N, I)-free chlorides such as eglestonite, implying that iodine was a late addition to the overall chemical system. Both the mineral and the mineral name have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA 2018-029). The mineral is named after Gail E. Dunning (b. 1937), a prominent field-collector of minerals from the New Idria mining district who has been responsible for the discovery of many new mercury-bearing minerals.

Stefanweissite, (Ca,REE)2Zr2(Nb,Ti)(Ti,Nb)2Fe2+O14, a new zirconolite-related mineral from the Eifel paleovolcanic region, Germany

AbstractThe new mineral stefanweissite, IMA2018-020, was discovered in sanidinite volcanic ejecta from the Laach Lake (Laacher See) paleovolcano, Eifel region, Rhineland-Palatinate, Germany. Associated minerals are sanidine, nosean, biotite, augite, titanite, ferriallanite-(La), magnetite, baddeleyite and a pyrochlore-group mineral. Stefanweissite is brown and reddish-brown, with adamantine lustre; the streak is light brown to yellow. It forms long-prismatic crystals up to 0.03 mm × 0.07 mm × 1.0 mm and acicular crystals up to 2 mm long and 0.02 mm thick typically combined in radiated aggregates in cavities in sanidinite. Dcalc. = 5.254 g/cm3. The mean refractive index calculated from the Gladstone–Dale equation is 2.260. The Raman spectrum shows the absence of hydrogen-bearing groups. The chemical composition is (electron microprobe, wt.%): CaO 7.63, MnO 2.51, FeO 7.86, Al2O3 0.25, La2O3 2.28, Ce2O3 6.54, Pr2O3 1.01, Nd2O3 1.59, ThO2 3.71, UO2 1.09, TiO2 17.32, ZrO2 28.03, HfO2 0.91, Nb2O5 19.96, total 99.69. The empirical formula based on 14 O atoms per formula unit is Ca1.13(Ce0.33La0.12Nd0.08Pr0.05)Σ0.58Th0.12U0.03Mn0.29Fe0.91Al0.04Zr1.89Hf0.04Ti1.80Nb1.19O14. The simplified formula is (Ca,REE)2Zr2(Nb,Ti)(Ti,Nb)2Fe2+O14. Stefanweissite is orthorhombic, with space group Cmca. The unit-cell parameters are: a = 7.2896(4) Å, b = 14.1435(5) Å, c = 10.1713(4) Å and V = 1048.68(7) Å3. The crystal structure was solved using single-crystal X-ray diffraction data. Stefanweissite is an analogue of zirconolite-3O with Nb dominant over Ti in one of two octahedral sites. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 2.983(100)(202), 2.897(71)(042), 1.828(38)(154, 400, 333), 1.793(25)(244), 1.767(16)(080), 1.517(10)(282), 1.187(19)(483, 1.11.3, 602). Type material is deposited in the collections of the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia, with the registration number 5191/1.

Nöggerathite-(Ce), (Ce,Ca)2Zr2(Nb,Ti)(Ti,Nb)2Fe2+O14, a New Zirconolite-Related Mineral from the Eifel Volcanic Region, Germany

The new mineral nöggerathite-(Ce) was discovered in a sanidinite volcanic ejectum from the Laach Lake (Laacher See) paleovolcano in the Eifel region, Rhineland-Palatinate, Germany. Associated minerals are sanidine, dark mica, magnetite, baddeleyite, nosean, and a chevkinite-group mineral. Nöggerathite-(Ce) has a color that ranges from brown to deep brownish red, with adamantine luster; the streak is brownish red. It occurs in cavities of sanidinite and forms long prismatic crystals measuring up to 0.02 × 0.03 × 1.0 mm, with twins and random intergrowths. Its density calculated using the empirical formula is 5.332 g/cm3. The Vickers hardness number (VHN) is 615 kgf/mm2, which corresponds to a Mohs’ hardness of 5½. The mean refractive index calculated using the Gladstone–Dale equation is 2.267. The Raman spectrum shows the absence of hydrogen-bearing groups. The chemical composition (electron microprobe holotype/cotype in wt %) is as follows: CaO 5.45/5.29, MnO 4.19/4.16, FeO 7.63/6.62, Al2O3 0.27/0.59, Y2O3 0.00/0.90, La2O3 3.17/3.64, Ce2O3 11.48/11.22, Pr2O3 1.04/0.92, Nd2O3 2.18/2.46, ThO2 2.32/1.98, TiO2 17.78/18.69, ZrO2 27.01/27.69, Nb2O5 17.04/15.77, total 99.59/99.82, respectively. The empirical formulae based on 14 O atoms per formula unit (apfu) are: (Ce0.59La0.165Nd0.11Pr0.05)Σ0.915Ca0.82Th0.07Mn0.50Fe0.90Al0.045Zr1.86Ti1.88Nb1.07O14 (holotype), and (Ce0.57La0.19Nd0.12Pr0.05Y0.06)Σ0.99Ca0.79Th0.06Mn0.49Fe0.77Al0.10Zr1.89Ti1.96Nb1.00O14 (cotype). The simplified formula is (Ce,Ca)2Zr2(Nb,Ti)(Ti,Nb)2Fe2+O14. Nöggerathite-(Ce) is orthorhombic, of the space group Cmca. The unit cell parameters are: a = 7.2985(3), b = 14.1454(4), c = 10.1607(4) Å, and V = 1048.99(7) Å3. The crystal structure was solved using single-crystal X-ray diffraction data. Nöggerathite-(Ce) is an analogue of zirconolite-3O, ideally CaZrTi2O7, with Nb dominant over Ti in one of two octahedral sites and REE dominant over Ca in the eight-fold coordinated site. The strongest lines of the powder X-ray diffraction pattern (d, Å (I, %) (hkl)) are: 2.963 (91) (202), 2.903 (100) (042), 2.540 (39) (004), 1.823 (15) (400), 1.796 (51) (244), 1.543 (20) (442), and 1.519 (16) (282), respectively. The type material is deposited in the collections of the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia (registration number 5123/1).

Agmantinite, Ag2MnSnS4, a new mineral with a wurtzite derivative structure from the Uchucchacua polymetallic deposit, Lima Department, Peru

AbstractAgmantinite, ideally Ag2MnSnS4, is a new mineral from the Uchucchacua polymetallic deposit, Oyon district, Catajambo, Lima Department, Peru. It occurs as orange–red crystals up to 100 μm across. Agmantinite is translucent with adamantine lustre and possesses a red streak. It is brittle. Neither fracture nor cleavage were observed. Based on the empirical formula the calculated density is 4.574 g/cm3. On the basis of chemically similar compounds the Mohs hardness is estimated at between 2 to 2½. In plane-polarised light agmantinite is white with red internal reflections. It is weakly bireflectant with no observable pleochroism with red internal reflections. Between crossed polars, agmantinite is weakly anisotropic with reddish brown to greenish grey rotation tints. The reflectances (RminandRmax) for the four standard wavelengths are: 19.7 and 22.0 (470 nm); 20.5 and 23.2 (546 nm); 21.7 and 2.49 (589 nm); and 20.6 and 23.6 (650 nm), respectively.Agmantinite is orthorhombic, space groupP21nm, with unit-cell parameters:a= 6.632(2),b= 6.922(2),c= 8.156(2) Å,V= 374.41(17) Å3,a:b:c0.958:1:1.178 andZ= 2. The crystal structure was refined toR= 0.0575 for 519 reflections withI >2σ(I). Agmantinite is the first known mineral of${M}_{\rm 2}^{\rm I} $MIIMIVS4type that is derived from wurtzite rather than sphalerite by ordered substitution of Zn, analogous to the substitution pattern for deriving stannite from sphalerite. The six strongest X-ray powder-diffraction lines derived from single-crystal X-ray diffraction data [din Å (intensity)] are: 3.51 (s), 3.32 (w), 3.11 (vs), 2.42 (w), 2.04 (m) and 1.88 (m). The empirical formula (based on 8 apfu) is (Ag1.94Cu0.03)Σ1.97(Mn0.98Zn0.05)Σ1.03Sn0.97S4.03.The crystal structure-derived formula is Ag2(Mn0.69Zn0.31)Σ1.00SnS4and the simplified formula is Ag2MnSnS4.The name is for the composition and the new mineral and mineral name have been approved by the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (IMA2014-083).

Gadolinite-(Nd), a new member of the gadolinite supergroup from Fe-REEdeposits of Bastnäs-type, Sweden

ABSTRACTA new member of the gadolinite supergroup, gadolinite-(Nd), IMA2016-013, ideally Nd2FeBe2Si2O10, was found in the Malmkärra mine, ~3.5 km WSW of Norberg, south-central Sweden, where it occurs in association with fluorbritholite-(Ce), västmanlandite-(Ce), dollaseite-(Ce), bastnäsite-(Ce) and tremolite. Gadolinite-(Nd) forms anhedral grains up to 150 µm in size, commonly occurring as aggregates of olive green colour. The crystals are transparent with vitreous to adamantine lustre. Gadolinite-(Nd) is brittle with conchoidal fracture, no cleavage or parting was observed. It has a white streak, the Mohs hardness is 6.5–7 and the calculated density is 4.86 g cm–3. Optically, the mineral is weakly pleochroic in shades of olive green, biaxial (–), nα = 1.78(1), nβ(calc.) = 1.80, nγ = 1.81(1) measured in white light, 2V(meas.) = 62(3)°. Electron-microprobe and laser ablation inductively coupled plasma mass spectrometry analysis [in wt.%] provided SiO221.77, Y2O35.49, La2O32.78, Ce2O314.04, Pr2O33.28, Nd2O319.27, Sm2O35.30, Eu2O30.24, Gd2O34.10, Tb2O30.36, Dy2O31.32, Ho2O30.18, Er2O30.38, MgO 0.51, CaO 0.14, MnO 0.10, FeO 10.62, B2O30.10, BeOcalc.8.99, H2Ocalc.0.55 and total 99.52 giving the following empirical formula (based on 2 Si): (Nd0.632Ce0.472Y0.268Sm0.168Gd0.125Pr0.110La0.094Dy0.039Ca0.014Er0.011Tb0.011Eu0.008Ho0.008)∑1.957(Fe0.816Mg0.070Mn0.008)∑0.894(Be1.984B0.016)∑2.000Si2O9.660OH0.337. A weak Raman vibration band at ~3525 cm–1confirms the presence of water in the structure. Gadolinite-(Nd) is monoclinic,P21/c, witha = 4.8216(3) Å,b = 7.6985(4) Å,c = 10.1362(6) Å, β = 90.234(4)°,V = 376.24(6) Å3andZ = 2. The strongest X-ray diffraction lines are [dobsin Å (hkl)Irel]: 4.830 (100) 72, 3.603 (021) 37, 3.191(-112) 52, 3.097 (013) 35, 2.888 (121) 100, 2.607(113) 49, 2.412 (200) 24. Along with the Malmkärra mine, gadolinite-(Nd) was also recorded also at Johannagruvan and Nya Bastnäs. The minerals of the gadolinite subgroup together with fluorbritholite-(Ce) incorporate the highest fraction of medium-to-heavy rare-earth elements among associated rare-earth element minerals in the Malmkärra mine and possibly in all Bastnäs-type deposits.

Fluorlamprophyllite, Na3(SrNa)Ti3(Si2O7)2O2F2, a new mineral from Poços de Caldas alkaline massif, Morro do Serrote, Minas Gerais, Brazil

ABSTRACTA new mineral species, fluorlamprophyllite (IMA2013-102), ideally Na3(SrNa)Ti3(Si2O7)2O2F2, has been found in the Poços de Caldas alkaline massif, Morro do Serrote, Minas Gerais, Brazil. Alternatively, the idealized chemical formula could be written as (SrNa)[(Na3Ti)F2][Ti2(Si2O7)2O2], setting the large interlayer cations before the cations of the layer. Fluorlamprophyllite is the F-analogue of lamprophyllite. It is associated with aegirine, analcime, natrolite, nepheline and microcline. Fluorlamprophyllite crystals are brownish-orange and bladed. The mineral is transparent with a pale yellow streak and an adamantine lustre. It is brittle and has a Mohs hardness of ~3; cleavage is perfect on {100} and no parting was observed. The calculated density is 3.484 g/cm3. Optically, fluorlamprophyllite is biaxial (+), with α = 1.735(7), β = 1.749(7) and γ = 1.775(9) and 2Vmeas = 72(3)°. An electron microprobe analysis produced an average composition (wt.%) (9 points) of Na2O 10.63(30), K2O 0.47(3), SiO2 30.51(13), SrO 18.30(24), MgO 0.81(17), Al2O3 0.23(2), CaO 1.11(7), MnO 5.03(38), TiO2 27.41(87), Fe2O3 2.45(37), F 2.86(23), plus H2O 1.00 (added to bring the total close to 100%), –O = F –1.20, with the total = 98.61%. The elements Nb and Ba were sought, but contents were below microprobe detection limits. The resultant chemical formula was calculated on the basis of 18 (O + F) atoms per formula unit. The addition of 1.00 wt.% H2O brought [F+(OH)] = 2 pfu, yielding (Na2.63Sr1.35Mn0.54Ca0.15Mg0.15K0.08)Σ4.90(Ti2.63Fe0.24Al0.04)Σ2.91Si3.89O16[F1.15(OH)0.85]Σ2.00. The mineral is monoclinic, with space group C2/m and unit-cell parameters a = 19.255(2), b = 7.0715(7), c = 5.3807(6) Å, β = 96.794(2)° and V = 727.5(1) Å3. The structure is a layered silicate inasmuch as the O atoms are arranged in well-defined, though not necessarily close-packed layers.

Ziminaite, Fe3+VO4, a new howardevansite-group mineral from the Bezymyannyi volcano, Kamchatka, Russia

The new mineral ziminaite, ideally Fe3+VO4, was found in fumarole sublimates at the Bezymyannyi volcano, Kamchatka, Russia. Ziminaite occurs as lamellar, tabular or flattened prismatic crystals up to 10 × 30 × 50 μm typically epitaxially overgrowing koksharovite, and as aggregates (up to 0.15 mm) associated with bannermanite in cavities in volcanic scoria. The mineral is translucent, yellowish-brown with an adamantine luster. The calculated density is 3.45 g cm− 3. In reflected light, ziminaite is light grey. Bireflectance is weak, internal reflections are deep yellow. The reflectance values [R max –R min, % (λ, nm)] are: 17.7–16.3 (470), 15.7–14.1 (546), 15.1–13.8 (589), 14.7–13.6 (650). Chemical composition (wt%) is: MgO 2.20, CaO 0.01, Al2O3 7.81, Fe2O3 27.18, TiO2 4.50, SiO2 0.26, P2O5 0.09, V2O5 57.01, total 99.06. The empirical formula, based on 24 O atoms, is: (Fe3 + 3.29Al1.48Ti0.54Mg0.53)Σ5.84(V6.05Si0.04P0.01)Σ6.10O24 (Z = 1). Ziminaite is triclinic, P $$\overline {1}$$ , a 8.012(4), b 9.345(5), c 6.678(3) A, α 106.992(10), β 101.547(8), γ 96.594(11)o, V 460.4(4) A3, Z = 6. The strongest reflections of the powder X-ray diffraction pattern [d,A(I)(hkl)] are: 3.751(17)(1–21, 12 − 1), 3.539(86)(120), 3.270(67)(01–2), 3.209(100)(2–20), 3.090(20)(2–11, 002), 3.041(18)(03 − 1, 02–2), 2.934(14)(12 − 2, 030) and 1.665(24)(023, 12 − 4). The crystal structure, solved from single-crystal data (R 1 = 0.085), is based upon heteropolyhedral framework built by VO4 tetrahedra and Fe3+-centred octahedra and five-fold polyhedra. Ziminaite belongs to the howardevansite group being its first member without species-defining uni- or divalent cations and with all large cation sites vacant. The mineral is named after the Zimina volcano situated near the discovery locality.

Kyawthuite, Bi3+Sb5+O4, a new gem mineral from Mogok, Burma (Myanmar)

AbstractKyawthuite, Bi3+Sb5+O4, is a new gem mineral found as a waterworn crystal in alluvium at Chaung-gyi-ah-le-ywa in the Chaung-gyi valley, near Mogok, Burma (Myanmar). Its description is based upon a single sample, which was faceted into a 1.61-carat gem.The composition suggests that the mineral formed in a pegmatite. Kyawthuite is monoclinic, space group I2/c, with unit cell dimensions a = 5.4624(4), b = 4.88519(17), c = 11.8520(8) Å, β = 101.195(7)°, V = 310.25(3) Å3and Z = 4. The colour is reddish orange and the streak is white. It is transparent with adamantine lustre. The Mohs hardness is 5½. Kyawthuite is brittle with a conchoidal fracture and three cleavages: {001} perfect, {110} and {110} good. The measured density is 8.256(5) g cm–3and the calculated density is 8.127 g cm–3. The mineral is optically biaxial with 2V = 90(2)°. The predicted indices of refraction are α = 2.194, β = 2.268, γ = 2.350. Pleochroism is imperceptible and the optical orientation is X = b; Y≈ c; Z ≈ a. Electron microprobe analyses, provided the empirical formula (Bi0.823+Sb0.183+)∑1.00(Sb0.995+Ta0.015+)∑1.00O4. The Raman spectrumis similar to that of synthetic Bi3+Sb5+O4. The infrared spectrum shows a trace amount of OH/H2O. The eight strongest powder X-ray diffraction lines are [dobs in Å(I)(hkl)]: 3.266(100)(112), 2.900(66)(112), 2.678(24)(200), 2.437(22)(020,114), 1.8663(21)(024), 1.8026(43)(116,220,204), 1.6264(23)(224,116) and 1.5288(28)(312,132). In the crystal structure of kyawthuite (R1 = 0.0269 for 593 reflections with Fo > 4σF), Sb5+O6 octahedrashare corners to form chequerboard-like sheets parallel to {001}. Atoms of Bi3+, located above and below the open squares in the sheets, form bonds to the O atoms in the sheets, thereby linking adjacent sheets into a framework. The Bi3+ atom is in lopsided 8 coordination,typical of a cation with stereoactive lone electron pairs. Kyawthuite is isostructural with synthetic β-Sb2O4 and clinocervantite (natural β-Sb2O4).

New Mineral NamesAndychristyiteCrimsoniteFerro-ferri-hornblendeKummeriteKuratiteOscarkempffiteOxo-Mangani-LeakeitePauladamsitePenberthycroftite

This New Mineral Names has entries for nine new minerals, including andychristyite, crimsonite, ferro-ferri-hornblende, kummerite, kuratite, oscarkempffite, oxo-mangani-leakeite, pauladamsite, and penberthycroftite. # Andychristyite* {#article-title-2} A.R. Kampf, M.A. Cooper, S.J. Mills, R.M. Housley and G.R. Rossman (2016) Lead-tellurium oxysalts from Otto Mountain near Baker, California, USA: XII. Andychristyite, PbCu2+Te6+O5(H2O), a new mineral with hcp stair-step layers. Mineralogical Magazine , 80(6), 1055–1065. Andychristyite (IMA 2015-024), ideally PbCu2+Te6+O5(H2O), is a new mineral found on the small dump outside the entrance to the Aga mine Otto Mountain near Baker, San Bernardino County, California, U.S.A. The new mineral was found as a few crystals in a small vug in quartz in association with timroseite. Andychristyite is a secondary oxidation-zone mineral presumed to have formed by oxidation of primary sulfides and tellurides during or following brecciation of quartz veins. It occurs as tablets flattened on {001}, up to ~50 μm in size, in sub-parallel aggregates. Crystals are bluish-green with very pale bluish-green streak, are transparent with adamantine luster, are brittle with irregular fracture, show perfect cleavage on {001}, and no twinning. Mohs hardness was not measured, but is estimated to be 2–3. The density was not measured; D calc = 6.304 g/cm3. Andychristyite does not fluoresce under UV light. It decomposes rapidly in dilute HCl at room temperature. The mineral is optically biaxial with undetermined sign, large 2 V , and moderate very pale blue-green to medium blue-green pleochroism. …

Delhuyarite-(Ce)–Ce4 Mg(Fe3+ 2W) [] (Si2 O7)2O6 (OH)2 – a new mineral of the chevkinite group, from the Nya Bastnäs Fe–Cu–REE deposit, Sweden

Delhuyarite-(Ce) is a new mineral (IMA no. 2016-091) with ideal formula Ce 4 Mg(Fe 3+ 2 W)□(Si 2 O 7 ) 2 O 6 (OH) 2 . It is named after Juan and Fausto de Elhuyar (Delhuyar), chemists and metallurgists, who in 1783 isolated tungsten metal for the first time. Associated minerals in the only known sample, from the Nya Bastnas Fe–Cu–REE deposit (Vastmanland, Sweden), include cerite-(Ce), tremolite–actinolite, percleveite-(Ce), bastnasite-(Ce), ferriallanite-(Ce), tornebohmite-(Ce), magnetite, chalcopyrite, quartz and scheelite. Delhuyarite-(Ce), which forms subhedral crystals up to 0.3 mm long, is brown–black with a dark brown streak and translucent with an adamantine lustre. It is pleochroic in black to rust red and optically biaxial (−). Calculated density and mean refractive index are 5.20 g cm −3 and 1.94, respectively. Chemical analyses (electron microprobe) gave (in wt%) La 2 O 3 14.58, Ce 2 O 3 23.29, Pr 2 O 3 1.89, Nd 2 O 3 6.13, Sm 2 O 3 0.74, Gd 2 O 3 0.37, Dy 2 O 3 0.03, Er 2 O 3 0.04, Yb 2 O 3 0.12, Y 2 O 3 0.22, CaO 0.76, Fe 2 O 3 12.86, MgO 2.43, Al 2 O 3 0.73, SiO 2 18.16, TiO 2 0.09, WO 3 15.53, H 2 O calc 1.33, F 0.05, Cl 0.03, O=(F, Cl) −0.03, sum 99.35, corresponding to an empirical formula: (Ce 1.89 La 1.19 Nd 0.48 Pr 0.15 Sm 0.06 Gd 0.03 Y 0.03 Ca 0.18 ) Σ4.01 (Fe 3+ 2.14 W 0.89 Mg 0.80 Al 0.19 Ti 0.02 ) Σ4.04 Si 4.01 O 20 (OH 1.96 F 0.04 ) Σ2 , based on 22 O atoms per formula unit (apfu). The presence of H 2 O is confirmed by IR-spectroscopy, from a strong absorption band at 3495 cm −1 . Delhuyarite-(Ce) is monoclinic, space group C 2 /m , with unit-cell parameters a =13.6020(6) A, b = 5.7445(3) A, c = 10.9996(5) A, β = 100.721(4)°, V = 844.47 (6) A 3 and Z = 2 (data for natural crystal). The crystal structure was refined to an R 1 index of 3.9% (natural crystal) and 1.8% (annealed). Delhuyarite-(Ce) has the same structural topology as chevkinite-subgroup minerals, e.g . chevkinite-(Ce). It is the only mineral of the group with a significant content of W 6+ = 0.89 apfu. In delhuyarite-(Ce), Mg is dominant at the M 1 site as in polyakovite-(Ce); the composition of the M 2, M 3 and M 4 sites is [(Fe 3+ 2 W□], with M 2 being 50% vacant.

Lead-tellurium oxysalts from Otto Mountain near Baker, California, USA: XII. Andychristyite, PbCu2+Te6+O5(H2O), a new mineral withhcpstair-step layers

AbstractAndychristyite, PbCu2+Te6+O5(H2O), is a new tellurate mineral from Otto Mountain near Baker, California, USA. It occurs in vugs in quartz in association with timroseite. It is interpreted as having formed from the partial oxidation of primary sulfides and tellurides during or following brecciation of quartz veins. Andychristyite is triclinic, space group P1̄, with unit-cell dimensionsa= 5.322(3),b= 7.098(4),c= 7.511 (4) Å, α = 83.486(7), β = 76.279(5), γ = 70.742(5)°,V= 260.0(2) Å3 andZ= 2. It forms as small tabular crystals up to ∼50 μm across, in sub-parallel aggregates. The colour is bluish green and the streak is very pale bluish green. Crystals are transparent with adamantine lustre. The Mohs hardness is estimated at between 2 and 3. Andychristyite is brittle with an irregular fracture and one perfect cleavage on {001}. The calculated density based on the empirical formula is 6.304 g/cm3. The mineral is optically biaxial, with large 2V, strong dispersion, and moderate very pale blue-green to medium blue-green pleochroism. The electron microprobe analyses (average of five) provided: PbO 43.21, CuO 15.38, TeO335.29, H2O 3.49 (structure), total 97.37 wt.%. The empirical formula (based on 6 O apfu) is: Pb0.98Cu2+0.98Te6+1.02O6H1.96. The Raman spectrum exhibits prominent features consistent with the mineral being a tellurate, as well as an OH stretching feature confirming a hydrous component. The eight strongest powder X-ray diffraction lines are [dobsin Å(I)(hkl)]: 6.71(16)(010), 4.76(17)(110), 3.274(100)(120,102,012), 2.641(27)(102, 211, 112), 2.434(23)(multiple), 1.6736(17)(multiple), 1.5882(21)(multiple) and 1.5133(15)(multiple). The crystal structure of andychristyite (R1= 0.0165 for 1511 reflections withFo> 4σF) consists of stair-step-likehcppolyhedral layers of Te6+O6and Cu2+O6octahedra parallel to {001}, which are linked in the [001] direction by bonds to interlayer Pb atoms. The structures of eckhardite, bairdite, timroseite and paratimroseite also contain stair-step-likehcppolyhedral layers.

Crimsonite, PbFe3+2(PO4)2(OH)2, the phosphate analogue of carminite from the Silver Coin mine, Valmy, Nevada, USA

AbstractCrimsonite (IMA2014-095), PbFe3+2(PO4)2(OH)2, the phosphate analogue of carminite, is a new mineral from the Silver Coin mine, Valmy, Iron Point district, Humboldt County, Nevada, USA, where it occurs as a low-temperature secondary mineral in association with fluorwavellite, goethite, hematite, hentschelite, plumbogummite and variscite on quartz. Crimsonite occurs in subparallel aggregates of deep red blades or plates flattened on {100} and up to 0.1 mm in maximum dimension. The streak is light purplish orange. Crystals are transparent and have adamantine lustre. The Mohs hardness is ∼3½, the tenacity is brittle, the fracture is irregular to splintery and an imperfect cleavage is likely on {101}. The calculated density is 5.180 g/cm3. Crimsonite is optically biaxial (+), with 2V = 85.5(5)° and γ – α = 0.011. Using the Gladstone-Dale relationship, the calculated indices of refraction are α = 2.021, β = 2.026 and γ = 2.032. The optical orientation isX=b;Y=a;Z=cand the pleochroism isXlight orange,Ylight yellow,Zred brown;Y<X< Z. Electron microprobe analyses provided PbO 40.69, CaO 0.60, ZnO 0.72, CuO 0.13, Fe2O323.36, Al2O30.34, V2O50.70, As2O512.05, P2O516.03, SO30.33 and H2O 3.64 (structure), total 98.59 wt.%. The empirical formula (based on 10 O apfu) is (Pb1.06Ca0.06)∑1.12(Fe1.71Zn0.05Al0.04Cu0.01)∑1.81(P1.32As0.61V0.05S0.02)∑2.00O8[(OH)1.64(H2O)0.36]∑2.00. Crimsonite is orthorhombic,Cccm,a= 16.2535(13),b= 7.4724(4),c= 12.1533(9) Å,V= 1476.04(17) Å3and Z = 8. The eight strongest lines in the powder X-ray diffraction pattern are [dobsin Å(I)(hkl)]: 5.86(42)(111); 4.53(45)(112); 3.485(64)(113); 3.190(100) (022); 3.026(40)(004); 2.902(54)(511); 2.502(77)(422) and 2.268(54)(224). The structure of crimsonite (R1= 3.57% for 740Fo> 4σF) contains FeO6octahedra that share edges to form dimers, which are then linked to other dimers by corner sharing to form chains along [010]. These chains are linked by PO4tetrahedra yielding sheets parallel to {001}. The sheets are linked to one another via bonds to 8-coordinated Pb2+atoms with non-stereoactive 6s2lone-electron pairs.

New Mineral NamesBackiteBluestreakiteCarducciiteChrysothalliteEckeriteEmmerichiteFerribushmakiniteFerro-Ferri-NybøiteGalloplumbogummiteHlousěkiteHydroxylwagneriteIshiharaiteMellizinkalitePeterandresenitePopoviteYurmarinite

This New Mineral Names has entries for 16 new minerals, including backite, bluestreakite, carducciite, chrysothallite, eckerite, emmerichite, ferribushmakinite, ferro-ferri-nyboite, galloplumbogummite, hlousěkite, hydroxylwagnerite, ishiharaite, mellizinkalite, peterandresenite, popovite, and yurmarinite. # Backite* {#article-title-2} K.T. Tait, V. Dicecco, N.A. Ball, F.C. Hawthorne, and A.R. Kampf (2014) Backite, Pb2Al(TeO6)Cl, a new tellurate mineral from the Grand Central Mine, Tombstone Hills, Cochise County, Arizona: Description and crystal structure. Canadian Mineralogist, 52(6), 935–942. Backite (IMA 2013-113), ideally Pb2Al(TeO6)Cl, is a new tellurate mineral discovered at the Grand Central mine located ¾ mile south of Tombstone, Arizona, U.S.A. Oxidized Ag- and Au-bearing galena and minor copper and zinc ores occur in faulted and fractured parts of a dike, and in brecciated footwall zones of the dike. Backite forms dark to pale blue-gray rosettes up to 0.15 mm consisting of hexagonal plates up to 0.08 mm exhibiting the forms {100}, {010}, and {001}. The rosettes are perched on microcrystalline quartz and associated with schieffelinite, oboyerite, rodalquilarite, cerussite, jarosite, and a new Pb-Cu tellurate-sulfate. Backite is moderately transparent with opacity increasing with intensity of color, has a very pale bluish-gray streak and adamantine luster. It has a perfect micaceous cleavage on {001}, is brittle with a splintery fracture and has a Mohs hardness of ~2–3. The density was not measured due to the lack of material; D calc = 5.573 g/cm3. The mineral does not fluoresce under UV light. Backite is optically uniaxial (−). The indices of refraction are greater than 1.80. Available liquids with higher refraction were reacting with the mineral; n calc = 1.878. Backite is pleochroic with O = …

Zincomenite, ZnSeO3, a new mineral from the Tolbachik volcano, Kamchatka, Russia

The new mineral zincomenite, β-ZnSeO3, is found in active fumaroles belonging to the Northern fumarole field at the First scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. It is associated with sofiite, sellaite, fluorite, halite, anhydrite, cotunnite, chubarovite, flinteite, etc . Zincomenite occurs as tabular, equant or prismatic crystals up to 0.2 mm sometimes combined in clusters up to 0.3 mm across or interrupted incrustations up to 0.7 × 1 cm overgrowing basalt scoria. Partial to complete pseudomorphs of zincomenite after sofiite are typical. The crystal forms are {101}, {010}, {100} and {013}. T-shaped twins with (012) as twin plane were found. Zincomenite is transparent, colourless, white or pale beige with adamantine lustre. Cleavage and parting were not observed and the fracture is uneven. D calc is 4.760 g cm−3. Zincomenite is optically biaxial (−), α = 1.744(5), β = 1.860(5), γ = 1.875(5). The IR spectrum is reported. The chemical composition (wt%, electron microprobe data) is: ZnO 42.53, SeO2 56.67, total 99.20. The empirical formula calculated on the basis of 3 O apfu is: Zn1.02Se0.99O3. Zincomenite is orthorhombic, Pbca, a = 7.1971(2), b = 6.2320(2), с = 11.9914(3) A, V = 537.84(2) A3 and Z = 8. The strongest reflections of the powder X-ray diffraction pattern [ d ,A( I )( hkl )] are: 4.612(26)(102), 3.601 (77)(200), 3.119(48)(210), 3.048(38)(113), 3.014(100)(211, 021), 2.996(56)(004), 2.771(19)(123, 104, 212), 2.459(23)(213, 023), 2.311(20)(123, 221, 204), and 2.162(19)(214, 024). Zincomenite is a representative of the CuSeO3 structure type. Its crystal structure, solved from single-crystal X-ray diffraction data ( R = 0.0188), contains layers formed by Zn2O8 dimers (consisting of edge-sharing ZnO5 trigonal bipyramids; each dimer shares four vertices with the neighbouring ones) linked via (SeO3)2− groups (with Se4+ in trigonal pyramidal coordination) to form an open framework. The mineral is named in allusion to its chemical composition: zinc selenite (the Greek μηναζ means moon , indicating selenium).

FLUORNATROPYROCHLORE, A NEW PYROCHLORE SUPERGROUP MINERAL FROM THE BOZIGUOER RARE EARTH ELEMENT DEPOSIT, BAICHENG COUNTY, AKESU, XINJIANG, CHINA

Fluornatropyrochlore is a new pyrochlore supergroup mineral species found in the intrusive alkali granite of the Boziguoer rare earth element deposit in Baicheng County, Akesu, Xinjiang Autonomous Region, China. This new mineral is found to be closely associated with microcline, albite, aegirine, a sodic amphibole, biotite, zircon, rutile, thorite, fluorite, fluocerite-(Ce), columbite-(Fe), xenotime-(Y), astrophyllite, chevkinite-(Ce), and fergusonite-(Y). Fluornatropyrochlore occurs mostly as anhedral crystals, rarely as subhedral grains, with a grain size of 0.02 to 0.25 mm. The color is brownish yellow to reddish orange. Other physical properties are: brittle, translucent to transparent, non-fluorescent, adamantine luster, light yellow streak, with Mohs hardness 4–4½, and calculated density 5.275 g cm−3. Fluornatropyrochlore is isotropic, n = 2.10(5) (589.9 nm). It has a cubic crystal structure, with unit-cell parameters determined using single-crystal X-ray diffraction as: a 10.5053(10) A, V 1159.4(2) A3, Z = 8, space group Fd 3 m . The strongest ten X-ray diffraction (XRD) peaks in the powder XRD pattern are [ d in A( I )( hkl )]: 6.0741(3)(111), 3.0416(100)(222), 2.6280(38)(004), 1.8568(34)(044), 1.5820(15)(226), 1.5148(4)(444), 1.3137(2)(008), 1.2045(3)(266), 1.1726(2)(048), and 1.0712(1)(448). Chemical analyses by a combination of electron microprobe, Fourier transform infrared spectroscopy (FTIR), and single crystal-structure refinement give its chemical composition as: Na2O 6.80, K2O 0.01, CaO 2.01, MgO 0.01, FeO 0.05, SrO 0.03, PbO 16.17, Ce2O3 4.29, La2O3 1.65, Nd2O3 0.41, Y2O3 0.42, SiO2 0.03, TiO2 1.36, UO2 5.81, Ta2O5 3.00, Nb2O5 53.42, F 3.19, Cl 0.02, ThO2, Sb2O5 0.01, ZrO2 0.01, MnO 0.04, SnO2 0.34, H2O not detected, with a sum of 98.21 wt.%. The empirical formula derived from its averaged composition is (Na1.03Pb0.34Ca0.17U0.10Th0.01Ce0.12La0.05Y0.02Nd0.01)Σ1.85(Nb1.88Ti0.08Ta0.06Sn0.01)Σ2.03O6.21F0.79 based on 7 anions per formula unit. The crystal structure was refined to an R index of 0.053 using Mo Ka X-ray intensity data. Site-scattering refinement analysis shows that the new mineral is characterized by F dominance at the Y site, Na dominance at the A site, and Nb dominance at the B site, based on the overall electroneutrality requirement of the structural formula.