Cesiokenopyrochlore, the First Natural Niobate with an Inverse Pyrochlore Structure

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Cesiokenopyrochlore, the First Natural Niobate with an Inverse Pyrochlore Structure. / Agakhanov, Atali A.; Kasatkin, Anatoly V.; Britvin, Sergey N.; Siidra, Oleg I.; Pautov, Leonid A.; Pekov, Igor V.; Karpenko, Vladimir Yu.

In: Canadian Mineralogist, Vol. 59, No. 1, 26.02.2021, p. 149-157.

Research output: Contribution to journal › Article › peer-review

Author

Agakhanov, Atali A. ; Kasatkin, Anatoly V. ; Britvin, Sergey N. ; Siidra, Oleg I. ; Pautov, Leonid A. ; Pekov, Igor V. ; Karpenko, Vladimir Yu. / Cesiokenopyrochlore, the First Natural Niobate with an Inverse Pyrochlore Structure. In: Canadian Mineralogist. 2021 ; Vol. 59, No. 1. pp. 149-157.

BibTeX

@article{e4d2ac822dd24ad295c1fee9e273a6b8,

title = "Cesiokenopyrochlore, the First Natural Niobate with an Inverse Pyrochlore Structure",

abstract = "Cesiokenopyrochlore is a new mineral belonging to the pyrochlore group. It was discovered in a specimen of granitic pegmatite collected at Tetezantsio, Betafo region, Madagascar. The mineral forms rough equant crystals up to 0.05 mm in size intergrown with b{\'e}hierite and rynersonite. Cesiokenopyrochlore is light-brown, translucent, with resinous luster. D calc. ¼ 5.984 g/cm 3. In reflected light it is light gray, isotropic, with strong light-brown internal reflections. The crystal structure was refined to R 1 ¼ 0.0212. The mineral is cubic, Fd -3m, a ¼ 10.444(1) A , V ¼ 1139.5(2) A 3, and Z ¼ 8. The strongest lines of the powder X-ray diffraction pattern [d, A , (I, %) (hkl)] are: 6.03 (37) (111), 3.70 (9) (220), 3.15 (100) (311), 3.02 (36) (222), 2.012 (17) (511, 333), 1.848 (19) (440), 1.576 (11) (622). The chemical composition is (wt.%; electron microprobe): Cs 2O 22.66, Na 2O 1.74, CaO 0.64, Nb 2O 5 20.87, Ta 2O 5 21.27, WO 3 30.67, H 2O (calc) 0.12, total 97.97. The empirical formula of the holotype specimen calculated on the basis of (Nb{\th}Ta{\th}W) ¼ 2 apfu and (O{\th}OH) ¼ 6 apfu and written according to the pyrochlore-supergroup nomenclature is Na 0.29Ca 0.06(Nb 0.81W 0.69Ta 0.50) R2[O 5.93(OH) 0.07] R6Cs 0.83. The simplified formula of the holotype specimen is A 2(Nb,W,Ta) R2O 6Cs. Cesiokenopyrochlore is the first natural niobate to adopt the inverse pyrochlore structure. ",

keywords = "Cesiokenopyrochlore, Cesium, Crystal structure, Granitic pegmatite, Inverse pyrochlore, Madagascar, New mineral, Niobate, Pyrochlore group, Tetezantsio",

author = "Agakhanov, {Atali A.} and Kasatkin, {Anatoly V.} and Britvin, {Sergey N.} and Siidra, {Oleg I.} and Pautov, {Leonid A.} and Pekov, {Igor V.} and Karpenko, {Vladimir Yu.}",

year = "2021",

month = feb,

day = "26",

doi = "10.3749/canmin.2000056",

language = "English",

volume = "59",

pages = "149--157",

journal = "Canadian Mineralogist",

issn = "0008-4476",

publisher = "Mineralogical Association of Canada",

number = "1",

}

RIS

TY - JOUR

T1 - Cesiokenopyrochlore, the First Natural Niobate with an Inverse Pyrochlore Structure

AU - Agakhanov, Atali A.

AU - Kasatkin, Anatoly V.

AU - Britvin, Sergey N.

AU - Siidra, Oleg I.

AU - Pautov, Leonid A.

AU - Pekov, Igor V.

AU - Karpenko, Vladimir Yu.

PY - 2021/2/26

Y1 - 2021/2/26

N2 - Cesiokenopyrochlore is a new mineral belonging to the pyrochlore group. It was discovered in a specimen of granitic pegmatite collected at Tetezantsio, Betafo region, Madagascar. The mineral forms rough equant crystals up to 0.05 mm in size intergrown with béhierite and rynersonite. Cesiokenopyrochlore is light-brown, translucent, with resinous luster. D calc. ¼ 5.984 g/cm 3. In reflected light it is light gray, isotropic, with strong light-brown internal reflections. The crystal structure was refined to R 1 ¼ 0.0212. The mineral is cubic, Fd -3m, a ¼ 10.444(1) A , V ¼ 1139.5(2) A 3, and Z ¼ 8. The strongest lines of the powder X-ray diffraction pattern [d, A , (I, %) (hkl)] are: 6.03 (37) (111), 3.70 (9) (220), 3.15 (100) (311), 3.02 (36) (222), 2.012 (17) (511, 333), 1.848 (19) (440), 1.576 (11) (622). The chemical composition is (wt.%; electron microprobe): Cs 2O 22.66, Na 2O 1.74, CaO 0.64, Nb 2O 5 20.87, Ta 2O 5 21.27, WO 3 30.67, H 2O (calc) 0.12, total 97.97. The empirical formula of the holotype specimen calculated on the basis of (NbþTaþW) ¼ 2 apfu and (OþOH) ¼ 6 apfu and written according to the pyrochlore-supergroup nomenclature is Na 0.29Ca 0.06(Nb 0.81W 0.69Ta 0.50) R2[O 5.93(OH) 0.07] R6Cs 0.83. The simplified formula of the holotype specimen is A 2(Nb,W,Ta) R2O 6Cs. Cesiokenopyrochlore is the first natural niobate to adopt the inverse pyrochlore structure.

AB - Cesiokenopyrochlore is a new mineral belonging to the pyrochlore group. It was discovered in a specimen of granitic pegmatite collected at Tetezantsio, Betafo region, Madagascar. The mineral forms rough equant crystals up to 0.05 mm in size intergrown with béhierite and rynersonite. Cesiokenopyrochlore is light-brown, translucent, with resinous luster. D calc. ¼ 5.984 g/cm 3. In reflected light it is light gray, isotropic, with strong light-brown internal reflections. The crystal structure was refined to R 1 ¼ 0.0212. The mineral is cubic, Fd -3m, a ¼ 10.444(1) A , V ¼ 1139.5(2) A 3, and Z ¼ 8. The strongest lines of the powder X-ray diffraction pattern [d, A , (I, %) (hkl)] are: 6.03 (37) (111), 3.70 (9) (220), 3.15 (100) (311), 3.02 (36) (222), 2.012 (17) (511, 333), 1.848 (19) (440), 1.576 (11) (622). The chemical composition is (wt.%; electron microprobe): Cs 2O 22.66, Na 2O 1.74, CaO 0.64, Nb 2O 5 20.87, Ta 2O 5 21.27, WO 3 30.67, H 2O (calc) 0.12, total 97.97. The empirical formula of the holotype specimen calculated on the basis of (NbþTaþW) ¼ 2 apfu and (OþOH) ¼ 6 apfu and written according to the pyrochlore-supergroup nomenclature is Na 0.29Ca 0.06(Nb 0.81W 0.69Ta 0.50) R2[O 5.93(OH) 0.07] R6Cs 0.83. The simplified formula of the holotype specimen is A 2(Nb,W,Ta) R2O 6Cs. Cesiokenopyrochlore is the first natural niobate to adopt the inverse pyrochlore structure.

KW - Cesiokenopyrochlore

KW - Cesium

KW - Crystal structure

KW - Granitic pegmatite

KW - Inverse pyrochlore

KW - Madagascar

KW - New mineral

KW - Niobate

KW - Pyrochlore group

KW - Tetezantsio

UR - http://www.scopus.com/inward/record.url?scp=85110276188&partnerID=8YFLogxK

U2 - 10.3749/canmin.2000056

DO - 10.3749/canmin.2000056

M3 - Article

VL - 59

SP - 149

EP - 157

JO - Canadian Mineralogist

JF - Canadian Mineralogist

SN - 0008-4476

IS - 1

ER -

ID: 77683391