The crystal chemistry of elsmoreite from the Hemerdon (Drakelands) mine, UK: Hydrokenoelsmoreite-3C and hydrokenoelsmoreite-6R

Stuart J. Mills; Andrew G. Christy; Mike S. Rumsey; John Spratt

doi:10.1180/minmag.2016.080.058

The crystal chemistry of elsmoreite from the Hemerdon (Drakelands) mine, UK: Hydrokenoelsmoreite-3C and hydrokenoelsmoreite-6R

Stuart J. Mills, Andrew G. Christy, Mike S. Rumsey, John Spratt

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

12 Citations (Scopus)

Abstract

A crystallographic and chemical study of two 'elsmoreite' samples (previously described as 'ferritungstite' from the Hemerdon mine (now known as the Drakelands mine), Devon, United Kingdom has shown them to be two different polytypes of hydrokenoelsmoreite. Hydrokenoelsmoreite-3C (HKE-3C) crystallizes in space group Fd3m, with the unit-cell parameter a = 10.3065(3) Å. Hydrokenoelsmoreite-6R (HKE-6R) crystallizes in space group R3, with the unit-cell parameters a = 7.2882(2) Å and c = 35.7056(14) Å. Chemical analyses showed that both polytypes have Na and Fe/Al substitution giving the formulae:(Na_0.28Ca_0.04K_0.02(H₂O)_0.20□_1.46)Σ2.00(W_1.47Fe³⁺_0.32Al_0.21As⁵⁺_0.01)Σ2.00[O_4.79(OH)_1.21]Σ6.00·(H₂O) (3C) and (Na_0.24Ca_0.04K_0.03(H₂O)_0.63□_1.06)Σ2.00(W_1.42Fe³⁺_0.49Al_0.08As⁵⁺_0.01)Σ2.00[O_4.65(OH)_1.35]Σ6.00·(H₂O) (6R). The doubling of the unit cell in the 6R phase is due to ordering of Na and (□,H₂O) in the A site; no long-range ordering is observed between W and Fe/Al in the B site.

Original language	English
Pages (from-to)	1195-1203
Number of pages	9
Journal	Mineralogical Magazine
Volume	80
Issue number	7
DOIs	https://doi.org/10.1180/minmag.2016.080.058
Publication status	Published - Dec 2016

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@article{fb38cdd93c25406da6e659cd0f32faab,

title = "The crystal chemistry of elsmoreite from the Hemerdon (Drakelands) mine, UK: Hydrokenoelsmoreite-3C and hydrokenoelsmoreite-6R",

abstract = "A crystallographic and chemical study of two 'elsmoreite' samples (previously described as 'ferritungstite' from the Hemerdon mine (now known as the Drakelands mine), Devon, United Kingdom has shown them to be two different polytypes of hydrokenoelsmoreite. Hydrokenoelsmoreite-3C (HKE-3C) crystallizes in space group Fd3m, with the unit-cell parameter a = 10.3065(3) {\AA}. Hydrokenoelsmoreite-6R (HKE-6R) crystallizes in space group R3, with the unit-cell parameters a = 7.2882(2) {\AA} and c = 35.7056(14) {\AA}. Chemical analyses showed that both polytypes have Na and Fe/Al substitution giving the formulae:(Na0.28Ca0.04K0.02(H2O)0.20□1.46)Σ2.00(W1.47Fe3+0.32Al0.21As5+0.01)Σ2.00[O4.79(OH)1.21]Σ6.00·(H2O) (3C) and (Na0.24Ca0.04K0.03(H2O)0.63□1.06)Σ2.00(W1.42Fe3+0.49Al0.08As5+0.01)Σ2.00[O4.65(OH)1.35]Σ6.00·(H2O) (6R). The doubling of the unit cell in the 6R phase is due to ordering of Na and (□,H2O) in the A site; no long-range ordering is observed between W and Fe/Al in the B site.",

keywords = "crystal structure, elsmoreite, phyllotungstite, pittongite, pyrochlore, tungstate",

author = "Mills, {Stuart J.} and Christy, {Andrew G.} and Rumsey, {Mike S.} and John Spratt",

note = "Publisher Copyright: {\textcopyright} 2016 by Walter de Gruyter Berlin/Boston 2016.",

year = "2016",

month = dec,

doi = "10.1180/minmag.2016.080.058",

language = "English",

volume = "80",

pages = "1195--1203",

journal = "Mineralogical Magazine",

issn = "0026-461X",

publisher = "Mineralogical Society",

number = "7",

}

TY - JOUR

T1 - The crystal chemistry of elsmoreite from the Hemerdon (Drakelands) mine, UK

T2 - Hydrokenoelsmoreite-3C and hydrokenoelsmoreite-6R

AU - Mills, Stuart J.

AU - Christy, Andrew G.

AU - Rumsey, Mike S.

AU - Spratt, John

PY - 2016/12

Y1 - 2016/12

N2 - A crystallographic and chemical study of two 'elsmoreite' samples (previously described as 'ferritungstite' from the Hemerdon mine (now known as the Drakelands mine), Devon, United Kingdom has shown them to be two different polytypes of hydrokenoelsmoreite. Hydrokenoelsmoreite-3C (HKE-3C) crystallizes in space group Fd3m, with the unit-cell parameter a = 10.3065(3) Å. Hydrokenoelsmoreite-6R (HKE-6R) crystallizes in space group R3, with the unit-cell parameters a = 7.2882(2) Å and c = 35.7056(14) Å. Chemical analyses showed that both polytypes have Na and Fe/Al substitution giving the formulae:(Na0.28Ca0.04K0.02(H2O)0.20□1.46)Σ2.00(W1.47Fe3+0.32Al0.21As5+0.01)Σ2.00[O4.79(OH)1.21]Σ6.00·(H2O) (3C) and (Na0.24Ca0.04K0.03(H2O)0.63□1.06)Σ2.00(W1.42Fe3+0.49Al0.08As5+0.01)Σ2.00[O4.65(OH)1.35]Σ6.00·(H2O) (6R). The doubling of the unit cell in the 6R phase is due to ordering of Na and (□,H2O) in the A site; no long-range ordering is observed between W and Fe/Al in the B site.

AB - A crystallographic and chemical study of two 'elsmoreite' samples (previously described as 'ferritungstite' from the Hemerdon mine (now known as the Drakelands mine), Devon, United Kingdom has shown them to be two different polytypes of hydrokenoelsmoreite. Hydrokenoelsmoreite-3C (HKE-3C) crystallizes in space group Fd3m, with the unit-cell parameter a = 10.3065(3) Å. Hydrokenoelsmoreite-6R (HKE-6R) crystallizes in space group R3, with the unit-cell parameters a = 7.2882(2) Å and c = 35.7056(14) Å. Chemical analyses showed that both polytypes have Na and Fe/Al substitution giving the formulae:(Na0.28Ca0.04K0.02(H2O)0.20□1.46)Σ2.00(W1.47Fe3+0.32Al0.21As5+0.01)Σ2.00[O4.79(OH)1.21]Σ6.00·(H2O) (3C) and (Na0.24Ca0.04K0.03(H2O)0.63□1.06)Σ2.00(W1.42Fe3+0.49Al0.08As5+0.01)Σ2.00[O4.65(OH)1.35]Σ6.00·(H2O) (6R). The doubling of the unit cell in the 6R phase is due to ordering of Na and (□,H2O) in the A site; no long-range ordering is observed between W and Fe/Al in the B site.

KW - crystal structure

KW - elsmoreite

KW - phyllotungstite

KW - pittongite

KW - pyrochlore

KW - tungstate

UR - http://www.scopus.com/inward/record.url?scp=85006741926&partnerID=8YFLogxK

U2 - 10.1180/minmag.2016.080.058

DO - 10.1180/minmag.2016.080.058

M3 - Article

SN - 0026-461X

VL - 80

SP - 1195

EP - 1203

JO - Mineralogical Magazine

JF - Mineralogical Magazine

IS - 7

ER -

The crystal chemistry of elsmoreite from the Hemerdon (Drakelands) mine, UK: Hydrokenoelsmoreite-3C and hydrokenoelsmoreite-6R

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