American Mineralogist, Volume 104, pages 625–629, 2019 New Mineral Names*,† DMITRIY I. BELAKOVSKIY1 AND FERNANDO CÁMARA2 1Fersman Mineralogical Museum, Russian Academy of Sciences, Leninskiy Prospekt 18 korp. 2, Moscow 119071, Russia 2Dipartimento di Scienze della Terra “Ardito Desio”, Universitá di degli Studi di Milano, Via Mangiagalli, 34, 20133 Milano, Italy IN THIS ISSUE This New Mineral Names has entries for 8 new minerals, including fengchengite, ferriperbøeite-(Ce), genplesite, heyerdahlite, millsite, saranchinaite, siudaite, vymazalováite and new data on lavinskyite-1M. FENGCHENGITE* X-ray diffraction pattern [d Å (I%; hkl)] are: 7.186 (55; 110), 5.761 (44; 113), 4.187 (53; 123), 3.201 (47; 028), 2.978 (61; 135). 2.857 (100; 044), G. Shen, J. Xu, P. Yao, and G. Li (2017) Fengchengite: A new species with 2.146 (30; 336), 1.771 (36; 24.11). Single-crystal X-ray diffraction data the Na-poor but vacancy-dominante N(5) site in the eudialyte group. shows the mineral is trigonal, space group R3m, a = 14.2467 (6), c = Acta Mineralogica Sinica, 37 (1/2), 140–151. 30.033(2) Å, V = 5279.08 Å3, Z = 3. The structure was solved by direct methods and refined to R = 0.043 for all unique I > 2σ(I) reflections. Fengchengite (IMA 2007-018a), Na Ca (Fe3+,) Zr Si (Si O ) 12 3 6 3 3 25 73 Fenchengite is the Fe3+ analog of eudialyte with a structural difference (H O) (OH) , trigonal, is a new eudialyte-group mineral discovered in 2 3 2 in vacancy dominant N5 site and splitting its Na site N1 into N1a and the agpaitic nepheline syenites and its pegmatite facies near the Saima N1b sites. It also chemically related to feklichevite and siudaite by the Town, ~60 km NNE of Fengcheng City, Liaoning Province, China. In the predominance Fe3+ in M2 site. The name is given for Fengcheng City near Saima agpaitic rocks, it occurs as an accessory or, locally, as rock-forming the type locality. The type material is deposited in the Geological Museum mineral up to 90% of the rock volume. The associated minerals include of China, Beijing, China. D.B. microcline, orthoclase, albite, nepheline, sodic amphiboles, aegirine, lamprophyllite, Na-poor rinkite, loparite, catapleiite, zircon, titanite, FERRIPERBØEITE-(CE)* Fe-rich phlogopite, rengeite, fluorapatite, REE-rich hydroxylellestadite, and hezuolinite. Fengchengite is considered to be crystallized directly L. Bindi, D. Holtstam, G. Fantappiè, U.B. Andersson, and P. Bonazzi (2018) 3+ 2+ from a REE-, U-, Th-, and Zr-rich alkaline magma enriched in volatile Ferriperbøeite-(Ce), [CaCe3]Σ=4[Fe Al2Fe ]Σ=4[Si2O7][SiO4]3O(OH)2, components. The mineral forms rose to deep-rose translucent to transparent a new member of the polysomatic epidote–törnebohmite series from vitreous anhedral to subhedral grains generally 1 to 7 mm with the largest the Nya Bastnäs Fe-Cu-REE deposit, Sweden. European Journal of over 15 mm. The crystal forms {001}, {100}, {110} are observed. The Mineralogy, 30(3), 537–544. streak is white. The mineral is brittle with uneven fracture and no cleav- 3+ 2+ Ferriperbøeite-(Ce) (IMA 2017-037), ideally [CaCe3]Σ4[Fe Al2Fe ]Σ4 age or parting. The micro-indentation hardness VHN25 = 562 (420–570) 2 [Si2O7][SiO4]3O(OH)2, monoclinic, is a new mineral species from the kg/mm corresponding to ~5 of the Mohs scale; Dmeas = 2.90(4), Dcalc = 2.839 g/cm3. Fengchengite does not fluoresce under UV radiation. In Nya Bastnäs Fe–Cu–REE skarn deposit in the Bergslagen mining region transmitted plane-polarized light, the mineral is not pleochroic (color not (Skinnskatteberg, Västmanland, south-central Sweden; 59°50ʹ47ʺN; given). It is optically uniaxial (+), ω = 1.603, ε = 1.607 (λ = 589.9 nm; 15°35ʹ15ʺE). Ferriperbøeite-(Ce) developed as a major phase of crys- accuracy not specified). IR spectrum shows bands at (cm−1; s = strong, tal aggregates largely replacing cerite-(Ce), whereas ferriallanite-(Ce) w = weak, sh = shoulder): 3541, 3442 (O–H stretching), 1654 (H–O–H occurs as a subordinate product of alteration, as crack-fillings and nar- bending), 1424w (?), 1013s, 975s, 934sh (Si–O-stretching), 739, 699sh, row rims on ferriperbøeite-(Ce). Other minerals in the type specimen are 663sh (mixed vibrations of the tetrahedral rings), 541, 474 (Fe3+–O stretch- cerite-(Ce), törnebohmite-(Ce), and ferriallanite-(Ce). Ferriperbøeite-(Ce) ing), 366 (lattice modes). The average of 16 WDS electron probe analyses forms brownish black subhedral short-prismatic crystals elongated along [010] up to 500 μm. Twinning is not observed. The streak is brown and is [wt% (range)]: Na2O 11.64 (10.10–12.34), K2O 0.52 (0.37–0.75), CaO 8.96 (8.55–9.33), MgO 0.07 (0.02–0.12), SrO 3.53 (2.89–3.90), the luster is vitreous. It is brittle and exhibits good {100} and imperfect 3 {001} cleavage. Mohs hardness is 6–7; Dcalc = 4.610 g/cm (unit cell BaO 0.02 (0–0.15), MnOtotal 0.93 (0.71–1.36), [MnO 0.10, Mn2O3 0.92], 3 parameters from single crystal diffraction) and Dcalc = 4.634 g/cm (unit- Fetotal6.07 (4.87–6.56) [FeO 0.69, Fe2O3 5.98 apportioned by Mössbauer cell parameters from powder diffraction). Crystals are transparent only in spectroscopy], La2O3 0.12 (0–0.23), Ce2O3 0.23 (0.09–0.29), Nd2O3 0.13 thin fragments, <20 μm. Refractive indices were not measured accurately (0.09–0.19), Sc2O3 0.01 (0–0.04), TiO2 0.38 (0.36–0.45), ZrO2 11.72 due to high absorption and numerous solid and fluid inclusions. Mean n = (11.02–11.78), SiO2 51.73 (49.46–52.35), Cr2O3 0.20 (0–0.52), Nb2O5 0.23 1.84 (from Gladstone-Dale relationship). The mineral is optically biaxial (0–0.44), Cl (wet chemistry) 1.13, H2O (thermogravimetry) 2.09, –O=Cl2 0.26, total 100.14. The empirical formula based on 78 anions and consider- (+), with 2V = 65(5)°. It is strongly pleochroic, from green throughout orange-brown, to deep red colors. The FTIR spectra show two relatively ing data on the crystal structure is [(Na3.0Na3.0)Ʃ6.00(Na5.28K0.330.39)Ʃ6.00]Ʃ12.00 –1 2+ 2+ 3+ 3+ sharp bands at 3590 and 3520 cm and two (or more) broad bands in the ( 2.71Sr0.20REE0.09)Ʃ3.00(Ca4.80Sr0.82Fe0.29Mg0.05Mn0.04)Ʃ6.00(Fe2.25Mn0.35 –1 region 3300‒3200 cm . The average of two electron probe WDS analyses Cr0.08 Ʃ0.32)Ʃ3.00(Zr2.86Ti0.09Nb0.05)Ʃ3.00(Si0.87Ti0.05 0.39)Ʃ1.00Si(Si24.00O73.00) is [wt% (range)]: CaO 4.53 (4.53–4.53), La2O3 17.62 (17.51–17.73), Ce2O3 [(H2O)2.93(OH)0.07]Ʃ3.00[(OH1.04Cl0.96)Ʃ2.00. The strongest lines of the powder 21.57 (21.47–21.67), Pr2O3 1.52 (1.51–1.52), Nd2O3 4.08 (4.03–4.13), Sm2O3 0.28 (0.25–0.30), Gd2O3 0.07 (0.06–0.07), Dy2O3 0.02 (0–0.04), Ho O 0.06 (0–0.12), Yb O 0.01 (0–0.02), Lu O 0.02 (0–0.03), Y O * All minerals marked with an asterisk have been approved by the IMA CNMMC. 2 3 2 3 2 3 2 3 † For a complete listing of all IMA-validated unnamed minerals and their codes, 0.06 (0.06–0.06), MgO 2.03 (1.97–2.08), FeO 2.89 (2.60–3.18), Fe2O3 see http://pubsites.uws.edu.au/ima-cnmnc/. (by Mössbauer) 7.92 (7.49–8.34), Al2O3 8.27 (8.26–8.28), SiO2 25.96 0003-004X/19/0004–625$05.00/DOI: http://dx.doi.org/10.2138/am-2019-NMN10447 625 Downloaded from http://pubs.geoscienceworld.org/msa/ammin/article-pdf/104/4/625/4670011/am-2019-nmn10447.pdf by guest on 23 September 2021 626 NEW MINERAL NAMES 2– 2– (25.67–26.25), TiO2 0.05 (0.03–0.07), P2O5 0.08 (0.06–0.09), F 0.21 (0.20– SO4 anions], 1010w [ν1(A1) = symmetric stretching of SO4 anions], 959w, 0.21), Cl 0.02 (0.02–0.02), –O=F2 0.09 (0.08–0.09), -O=Cl2 0, H2O (on the 932w, 798w (Sn···O–H bending vibrations), 651, 627 [ν4(F2) – bending 2– basis of OH= 1.87 pfu) 1.50, total 98.68. The empirical formulae based of SO4 anions], 533 (Sn–O stretching), 457 (possible librational vibra- on 13 cations (except H) pfu is (Ca0.92La1.23Ce1.50Pr0.10Nd0.27Sm0.02Y0.01)Σ4.05 tions of H2O). The average of four electron microprobe WDS analyses is 2+ 3+ (Al1.85Fe0.46Fe 1.13Mg0.57Ti0.01)Σ4.02(Si4.92P0.01)Σ4.93O20(OH1.87F0.12Cl0.01). The [wt% (range)]: CaO 28.67 (28.49–28.84), Al2O3 0.11 (0.04–0.16), GeO2 eight strongest X-ray powder diffraction lines are [d Å (I%; hkl)]: 3.520 0.50 (0.35–0.63), SnO2 24.20 (24.02–24.45), SO3 27.25 (27.06–27.53), (45; 212), 2.997 (100; 115), 2.868 (45; 020), 2.771 (40; 015), 2.682 (34; H2O (by structure, 3 H2O pfu) 18.34, total 99.07. The empirical formulae 203), 2.633 (60; 312), 2.159 (27; 225), 2.100 (35; 222). Unit-cell pa- based on 17 O pfu is Ca3.01(Sn0.95Ge0.03Al0.01)S0.99S2.01O8(OH)6·3H2O. The rameters refined from the powder data with whole-pattern fitting are a = strongest X-ray powder diffraction lines are [d Å (I%; hkl)]: 7.38 (68; 8.9317(5), b = 5.7441(4), c = 17.6164(9) Å, β = 116.034(4)°, V = 812.09 100), 4.259 (46; 110), 3.503 (15; 201), 3.383 (100; 112), 2.616 (13; 203), 3 Å .