J 2019

Vandermeerscheite, a new uranyl vanadate related to carnotite, from Eifel, Germany

PLÁŠIL, Jakub; Anthony R. KAMPF; Radek ŠKODA a Jiri CEJKA

Základní údaje

Originální název

Vandermeerscheite, a new uranyl vanadate related to carnotite, from Eifel, Germany

Autoři

PLÁŠIL, Jakub; Anthony R. KAMPF; Radek ŠKODA a Jiri CEJKA

Vydání

Journal of Geosciences, Praha, Česká geologická společnost, 2019, 1802-6222

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10504 Mineralogy

Stát vydavatele

Česká republika

Utajení

není předmětem státního či obchodního tajemství

Odkazy

Impakt faktor

Impact factor: 1.279

Označené pro přenos do RIV

Ano

Kód RIV

RIV/00216224:14310/19:00113498

Organizační jednotka

Přírodovědecká fakulta

EID Scopus

Klíčová slova anglicky

vandermeerscheite; uranyl vanadate; new mineral; carnotite group; crystal structure

Štítky

Příznaky

Mezinárodní význam, Recenzováno
Změněno: 2. 4. 2020 11:16, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

Vandermeerscheite (IMA2017-104), K-2[(UO2)(2)V2O8]center dot 2H(2)O, is a new uranyl-vanadate mineral from the Schellkopf quarry, Eifel, Germany. The new mineral occurs in cavities of volcanic rocks, mostly growing on phillipsite-K. It forms rosette-like aggregates of thin blades up to 50 mu m long. Crystals are flattened on {10 (1) over bar} , and elongated on [101], with crystal forms {010}, {10 (1) over bar} and {111}; crystals are transparent with a vitreous luster. Vandermeerscheite is non-fluorescent under both long- and short-wavelength ultraviolet radiation. The Mohs hardness is similar to 2. The calculated density is 4.502 g. cm(-3) based on the empirical formula; 4.507 g.cm(-3) for the ideal formula. Vandermeerscheite dissolves easily in dilute HCl at room temperature. The new mineral is biaxial (-), with alpha = 1.83 (calc.), beta = 1.90(1), gamma = 1.91(1) (measured in white light at 22 degrees C). The measured 2V is 40(10)degrees estimated from conoscopic observation of interference figure; dispersion is moderate r < v. No pleochroism was observed. Optical orientation X approximate to perpendicular to {10<(1)over bar>}, Y approximate to [101], Z = b. The empirical formula of vandermeerscheite (on the basis of 14 O apfu) is (K-1.87 Ca0.05Na0.04)(Sigma 1.96)[(U-1.0(05) O-2)(2)V-1.99 O-8]center dot 2H(2)O. Raman spectrum is dominated by the vibrations of UO22+. and V2O8 units. Vandermeerscheite is monoclinic, P2(1)/n, a = 8.292(2), b = 8.251(3), c = 10.188(3)angstrom, beta = 110.84(3)degrees, V= 651.4(4) angstrom(3), and Z = 2. The seven strongest powder X-ray diffraction lines are [d(obs), angstrom (I, %)(hkl) ]: 7.49 (100) ((1) over bar 01), 4.147 (22) (020), 3.738 (32) ((2) over bar 02), 3.616 (20) ((1) over bar 21), 3.254 (31) (112, 121), 3.132 (21) ((1) over bar 22, 022), 2.989 (41) (211, 013). The crystal structure of vandermeerscheite was refined from the single-crystal X-ray data to R = 0.0801 for 644 independent observed reflections, with I-obs > 3 sigma(I). The structure, which differs from carnotite in symmetry, is based upon uranyl vanadate sheets of francevillite topology; in the interlayer, there are K+ cations and H2O groups that provide inter-sheet linkage. The new mineral honors Belgian amateur mineralogist and famous mineral photographer Eddy Van Der Meersche, who discovered the new mineral.