2017
Linekite, K2Ca3[(UO2)(CO3)(3)](2)center dot 8H(2)O, a new uranyl carbonate mineral from Jachymov, Czech Republic
PLÁŠIL, Jakub, Jiří ČEJKA, Jiří SEJKORA, Jan HLOUŠEK, Radek ŠKODA et. al.Základní údaje
Originální název
Linekite, K2Ca3[(UO2)(CO3)(3)](2)center dot 8H(2)O, a new uranyl carbonate mineral from Jachymov, Czech Republic
Autoři
PLÁŠIL, Jakub (203 Česká republika), Jiří ČEJKA (203 Česká republika), Jiří SEJKORA (203 Česká republika), Jan HLOUŠEK (203 Česká republika), Radek ŠKODA (203 Česká republika, garant, domácí), Milan NOVÁK (203 Česká republika, domácí), Michal DUŠEK (203 Česká republika), Ivana CISAROVA (203 Česká republika), Ivan NEMEC (203 Česká republika) a Jana EDEROVA (203 Česká republika)
Vydání
Journal of Geosciences, Praha, Česká geologická společnost, 2017, 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
Impakt faktor
Impact factor: 1.415
Kód RIV
RIV/00216224:14310/17:00100334
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000417045600004
Klíčová slova anglicky
Linekite; uranyl carbonate; crystal structure; Raman spectroscopy; Jachymov
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 6. 4. 2018 12:59, Ing. Nicole Zrilić
Anotace
V originále
Linekite, K2Ca3[(UO2)(CO3)(3)](2)center dot 8H(2)O, is a new uranyl tricarbonate mineral from Jachymov, Western Bohemia, Czech Republic. It occurs in association with grimselite, andersonite, liebigite, cejkaite, schrockingerite, agricolaite, jezekite and braunerite. Linekite forms from uranium-rich aqueous solutions and its origin is associated with post-mining processes. Linekite is orthorhombic, space group Pnnm, with a = 17.0069(5) angstrom, b = 18.0273(5) angstrom, c = 18.3374(5) angstrom and V = 5622.1(2) angstrom(3), and Z = 8. It forms tabular, mostly isometric crystals, up to c. 0.5 mm across, typically in multiple intergrowths. The color is pale olive to khaki green and it has a greenish white to yellowish white streak. Crystals are transparent and have vitreous luster. The Mohs hardness is estimated to be between 2 and 3. Linekite is brittle with an uneven fracture and perfect cleavage on {100} and very good cleavage on {010}. It exhibits intense greenish yellow luminescence under both short-(254 nm) and long-wave (366 nm) UV radiation. The calculated density is 2.922 g/cm(3). The mineral is biaxial (+) with indices of refraction, alpha = 1.546(2), beta = 1.550, gamma = 1.562(2). The 2V(obs) is moderate; the calculated 2V is + 60 degrees. Optical orientation: Y = a, X = b, Z = c. The electron microprobe analyses (average of 28) provided: Na2O 0.06, K2O 6.89, CaO 14.11, CuO 0.12, UO3 48.76, CO2 * 22.51, H2O* 12.20 (similar to 12.9 from TG) (*calculated), total 104.65 wt%. The empirical formula (based on 30.22 O apfu) is: (K1.73Na0.02)(Sigma 1.75)(Ca2.97Cu0.02)(Sigma 2.99)[(UO2)(CO3)(3)](2.02)(H2O)(8.00). The Raman and infrared spectra exhibit prominent features consistent with the mineral being a hydrated uranyl tricarbonate, with fundamental vibrations of H2O molecules, CO(3)(2-)anions and UO22+ ions. The seven strongest powder X-ray diffraction lines are [d(obs) in angstrom (hkl) I-rel]: 8.627 (200) 100, 6.436 (022) 60, 5.935 (212) 11, 5.153 (222) 43, 4.592 (004) 19, 4.505 (040) 12 and 4.053 (204) 15. The structure of linekite was refined from single-crystal X-ray data to R = 0.034 for 4468 unique observed reflections (I-obs > 3 sigma I). The structure consists of prominent (Ca(H2O)(2)[(UO2)(CO3)(3)])(2-) layers parallel to (100), which define a square grid, leading to a strong tetragonal pseudosymmetry of linekite. Between the layers, disordered K+ cations and H2O molecules are localized. The structure is closely related to other uranyl tricarbonate minerals, e.g., albrechtschraufite and andersonite, due to the presence of a very characteristic paddle-wheel motif, Ca[(UO2)(CO3)(3)](4) Ca.
Návaznosti
MUNI/A/1316/2015, interní kód MU |
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