J 2021

The mineralogy of the historical Mochalin Log REE deposit, South Urals, Russia. Part IV. Alexkuznetsovite-(La), La2Mn(CO3)(Si2O7), alexkuznetsovite-(Ce), Ce2Mn(CO3)(Si2O7) and biraite-(La), La2Fe2+(CO3)(Si2O7), three new isostructural minerals and a definition of the biraite group

KASATKIN, Anatoly V.; Natalia V. ZUBKOVA; Igor V. PEKOV; Nikita V. CHUKANOV; Radek ŠKODA et. al.

Základní údaje

Originální název

The mineralogy of the historical Mochalin Log REE deposit, South Urals, Russia. Part IV. Alexkuznetsovite-(La), La2Mn(CO3)(Si2O7), alexkuznetsovite-(Ce), Ce2Mn(CO3)(Si2O7) and biraite-(La), La2Fe2+(CO3)(Si2O7), three new isostructural minerals and a definition of the biraite group

Autoři

KASATKIN, Anatoly V.; Natalia V. ZUBKOVA; Igor V. PEKOV; Nikita V. CHUKANOV; Radek ŠKODA (203 Česká republika, domácí); Atali A. AGAKHANOV; Dmitriy I. BELAKOVSKIY; Sergey N. BRITVIN a Dmitry Yu. PUSHCHAROVSKY

Vydání

Mineralogical Magazine, Mineralogical Society, 2021, 0026-461X

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10504 Mineralogy

Stát vydavatele

Velká Británie a Severní Irsko

Utajení

není předmětem státního či obchodního tajemství

Odkazy

Impakt faktor

Impact factor: 2.131

Kód RIV

RIV/00216224:14310/21:00124486

Organizační jednotka

Přírodovědecká fakulta

DOI

UT WoS

000723015700012

EID Scopus

2-s2.0-85112363418

Klíčová slova anglicky

alexkuznetsovite-(La); alexkuznetsovite-(Ce); biraite-(La); new mineral; rare-earth carbonate-silicate; crystal structure; biraite group; Mochalin Log; South Urals

Štítky

Příznaky

Mezinárodní význam, Recenzováno
Změněno: 4. 4. 2022 15:45, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

Three new isostructural minerals, alexkuznetsovite-(La), ideally La2Mn(CO3)(Si2O7), alexkuznetsovite-(Ce) Ce2Mn(CO3)(Si2O7) and biraite-(La) La2Fe2+(CO3)(Si2O7), were discovered in polymineralic nodules from the Mochalin Log REE deposit, South Urals, Russia. The new minerals form anhedral grains up to 0.3 mm x 0.4 mm [alexkuznetsovite-(La)], 0.5 mm x 0.9 mm [alexkuznetsovite-(Ce)] and 0.2 mm x 1.2 mm [biraite-(La)] embedded in granular aggregates consisting of different REE minerals [allanite-(Ce)/-(La), bastnasite-(Ce)/-(La), fluorbritholite-(Ce), perbOeite-(Ce)/-(La), percleveite-(Ce)/-(La) and tornebohmite-(Ce)/-(La)]. All three new species are brown to dark brown, translucent in thin fragments, with white streak, vitreous lustre and Mohs' hardness of similar to 5. D-calc = 4.713 [alexkuznetsovite-(La)], 4.687 [alexkuznetsovite-(Ce)] and 4.682 [biraite-La)] g.cm(-3). Their empirical formulae, calculated on the basis of 2 Si and 10 O apfu, are: alexkuznetsovite-(La): (La0.98Ce0.89Nd0.10Pr0.05)(Sigma 2.02)Mn0.502+Fe0.292+Ca0.12Mg0.03(CO3)(0.94)(HCO3)(0.06) (Si2O7); alexkuznetsovite-(Ce): (Ce0.96La0.78Nd0.16Pr0.07)(Sigma 1.97)Th0.01Mn0.502+Fe0.332+Ca0.14Mg0.02(CO3)(0.93)(HCO3)(0.07)(Si2O7); and biraite-(La): (La0.95Ce0.87Nd0.08Pr0.04)(Sigma 1.94)Th0.01Ca0.12Fe0.442+Mn0.382+Mg0.07(CO3)(0.88)(HCO3)(0.12)(Si2O7). The new minerals are monoclinic, P2(1)/c and Z = 4. The unit-cell parameters of alexkuznetsovite-(La)/alexkuznetsovite-(Ce)/biraite-(La) are: a = 6.5642(3)/6.5764(4)/6.5660(10), b = 6.7689(3)/6.7685(4)/6.7666(11), c = 18.7213(10)/18.7493(15)/18.698(3) angstrom, beta = 108.684(6)/108.672(8)/108.952(16)degrees and V = 788.00(7)/790.66(10)/785.7(2) angstrom(3). The crystal structures are solved from single-crystal X-ray diffraction data; R = 0.0628 [alexkuznetsovite-(La)], 0.0589 [alexkuznetsovite-(Ce)] and 0.1193 [biraite-(La)]. A new biraite group is defined; it includes isostructural biraite-(Ce) and the three new minerals described herein. The rootname alexkuznetsovite is given in honour of the Russian mineral collector Alexey M. Kuznetsov (born 1962) who provided samples in which all three new minerals were found. The Levinson's suffix-modifier -(La) or -(Ce) indicates the predominance of La or Ce among REE in the mineral. Biraite-(La) is named as an analogue of biraite-(Ce) with La prevailing among REE.