Oxybismutomicrolite, a new pyrochlore-supergroup mineral from the Malkhan pegmatite field, Central Transbaikalia, Russia

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F20%3A00114382" target="_blank" >RIV/00216224:14310/20:00114382 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1180/mgm.2020.25" target="_blank" >https://doi.org/10.1180/mgm.2020.25</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1180/mgm.2020.25" target="_blank" >10.1180/mgm.2020.25</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Oxybismutomicrolite, a new pyrochlore-supergroup mineral from the Malkhan pegmatite field, Central Transbaikalia, Russia

Popis výsledku v původním jazyce

Oxybismutomicrolite, ideally [(Bi3+,#)(2)]Sigma 4+Ta2O6O, where # = subordinate substituents, such as Na+, Ca2+ and vacancy OD, is a microlitegroup, pyrochlore-supergroup mineral discovered at the Solnechnaya ('Sunny') pegmatite vein, Malkhan pegmatite field, Zabaykalskiy Kray, Central Transbaikalia, Russia. It forms rough octahedral crystals up to 1 mm across and equant grains up to 2 mm across embedded in an albite-lepidolite-elbaite complex. Other associated minerals are Bi-rich fluornatromicrolite, bismutotantalite and stibiotantalite. The new mineral is black, with resinous lustre; the streak is greyish white. It is non-fluorescent under ultraviolet light. Oxybismutomicrolite is brittle, with Mohs' hardness of similar to 5. Cleavage is not observed, fracture is uneven. D-meas. = 6.98(2) g/cm(3) and D-calc. = 7.056 g/cm(3). The mineral is optically isotropic. The mean refractive index calculated from the Gladstone-Dale equation is 2.184. The infrared spectrum shows the absence of H2O molecules and OH groups. The chemical composition is (electron microprobe, wt.%): Na2O 3.45, CaO 2.88, MnO 0.31, PbO 0.76, Bi2O3 29.81, ThO2 0.18, TiO2 3.89, SnO2 1.77, Nb2O5 4.50, Ta2O5 51.08, F 1.17, O = F -0.49, total 99.31. The empirical formula, on the basis of 2 cations at the B site, is (Bi0.79Na0.68Ca0.32Mn0.03Pb0.02 square(0.)(16))Sigma(2.00)(Ta1.42Ti0.30Nb0.23Sn0.07)(Sigma 2.00) O-6.00(O0.52F0.38 square(0.10))(Sigma 1.00). The crystal structure refinement (R = 0.019) gave the following data: cubic, Fd (3) over barm, a = 10.4746(11) angstrom, V = 1149.2(4) angstrom(3) and Z= 8. The eight strongest lines of the powder X-ray diffraction pattern [d, angstrom(I, %)(hkl)] are: 6.051(12)(111), 3.160(10)(311), 3.026(100)(222), 2.621(32)(400), 1.854(33)(440), 1.581(27)(622), 1.514(7)(444) and 1.203(7)(662). Type material is deposited in the collections of the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia, registration number 5409/1.

Název v anglickém jazyce

Oxybismutomicrolite, a new pyrochlore-supergroup mineral from the Malkhan pegmatite field, Central Transbaikalia, Russia

Popis výsledku anglicky

Oxybismutomicrolite, ideally [(Bi3+,#)(2)]Sigma 4+Ta2O6O, where # = subordinate substituents, such as Na+, Ca2+ and vacancy OD, is a microlitegroup, pyrochlore-supergroup mineral discovered at the Solnechnaya ('Sunny') pegmatite vein, Malkhan pegmatite field, Zabaykalskiy Kray, Central Transbaikalia, Russia. It forms rough octahedral crystals up to 1 mm across and equant grains up to 2 mm across embedded in an albite-lepidolite-elbaite complex. Other associated minerals are Bi-rich fluornatromicrolite, bismutotantalite and stibiotantalite. The new mineral is black, with resinous lustre; the streak is greyish white. It is non-fluorescent under ultraviolet light. Oxybismutomicrolite is brittle, with Mohs' hardness of similar to 5. Cleavage is not observed, fracture is uneven. D-meas. = 6.98(2) g/cm(3) and D-calc. = 7.056 g/cm(3). The mineral is optically isotropic. The mean refractive index calculated from the Gladstone-Dale equation is 2.184. The infrared spectrum shows the absence of H2O molecules and OH groups. The chemical composition is (electron microprobe, wt.%): Na2O 3.45, CaO 2.88, MnO 0.31, PbO 0.76, Bi2O3 29.81, ThO2 0.18, TiO2 3.89, SnO2 1.77, Nb2O5 4.50, Ta2O5 51.08, F 1.17, O = F -0.49, total 99.31. The empirical formula, on the basis of 2 cations at the B site, is (Bi0.79Na0.68Ca0.32Mn0.03Pb0.02 square(0.)(16))Sigma(2.00)(Ta1.42Ti0.30Nb0.23Sn0.07)(Sigma 2.00) O-6.00(O0.52F0.38 square(0.10))(Sigma 1.00). The crystal structure refinement (R = 0.019) gave the following data: cubic, Fd (3) over barm, a = 10.4746(11) angstrom, V = 1149.2(4) angstrom(3) and Z= 8. The eight strongest lines of the powder X-ray diffraction pattern [d, angstrom(I, %)(hkl)] are: 6.051(12)(111), 3.160(10)(311), 3.026(100)(222), 2.621(32)(400), 1.854(33)(440), 1.581(27)(622), 1.514(7)(444) and 1.203(7)(662). Type material is deposited in the collections of the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia, registration number 5409/1.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10504 - Mineralogy

Projekt

<a href="/cs/project/GA19-05198S" target="_blank" >GA19-05198S: Greisenizace a albitizace - geologické procesy s potenciálem koncentrovat některé kritické suroviny pro moderní technologie</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Mineralogical Magazine

ISSN

0026-461X

e-ISSN

1471-8022

Svazek periodika

84

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

11

Strana od-do

444-454

Kód UT WoS článku

000545319900009

EID výsledku v databázi Scopus

2-s2.0-85091104426