Brumadoite, a new copper tellurate hydrate, from Brumado, Bahia, Brazil

Atencio, Daniel; Roberts, Andrew C.; Matioli, P. A.; Stirling, J. A. R.; Venance, K. E.; Doherty, W.; Stanley, Chris J.; Rowe, Ralph; Carpenter, G.J.C.; Coutinho, José Moacyr Vianna

doi:10.1180/minmag.2008.072.6.1201

Cited by 3 publications

(2 citation statements)

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“…Herak et al, 2005;Choi et al, 2008;Zhu et al, 2014;Chakraborty, 2019;Wang et al, 2019), while copper tellurium oxides in general are of interest for their magnetic properties (Norman, 2016(Norman, , 2018Inosov, 2018). Recently, we undertook a study to generate synthetic analogues of rare copper(II) tellurate minerals without known crystal structures, such as brumadoite [Cu 3 (Te VI O 4 )-(OH) 4 Á5H 2 O; Atencio et al (2008)] and xocomecatlite [Cu 3 (Te VI O 4 )(OH) 4 ; Williams (1975)]. These experiments tended to produce phases with X-ray powder diffraction (XRPD) patterns similar to Cu II 3 Te VI O 6 , indicating the stability of phases with this formula.…”

Section: Introductionmentioning

confidence: 99%

Polytypism in mcalpineite: a study of natural and synthetic Cu₃TeO₆

Missen¹,

Mills²,

Canossa³

et al. 2022

Acta Crystallogr B Struct Sci Cryst Eng Mater

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Synthetic and naturally occurring forms of tricopper orthotellurate, CuII 3TeVIO6 (the mineral mcalpineite) have been investigated by 3D electron diffraction (3D ED), X-ray powder diffraction (XRPD), Raman and infrared (IR) spectroscopic measurements. As a result of the diffraction analyses, CuII 3TeVIO6 is shown to occur in two polytypes. The higher-symmetric CuII 3TeVIO6-1C polytype is cubic, space group Ia 3, with a = 9.537 (1) Å and V = 867.4 (3) Å3 as reported in previous studies. The 1C polytype is a well characterized structure consisting of alternating layers of CuIIO6 octahedra and both CuIIO6 and TeVIO6 octahedra in a patchwork arrangement. The structure of the lower-symmetric orthorhombic CuII 3TeVIO6-2O polytype was determined for the first time in this study by 3D ED and verified by Rietveld refinement. The 2O polytype crystallizes in space group Pcca, with a = 9.745 (3) Å, b = 9.749 (2) Å, c = 9.771 (2) Å and V = 928.3 (4) Å3. High-precision XRPD data were also collected on CuII 3TeVIO6-2O to verify the lower-symmetric structure by performing a Rietveld refinement. The resultant structure is identical to that determined by 3D ED, with unit-cell parameters a = 9.56157 (19) Å, b = 9.55853 (11) Å, c = 9.62891 (15) Å and V = 880.03 (2) Å3. The lower symmetry of the 2O polytype is a consequence of a different cation ordering arrangement, which involves the movement of every second CuIIO6 and TeVIO6 octahedral layer by (1/4, 1/4, 0), leading to an offset of TeVIO6 and CuIIO6 octahedra in every second layer giving an ABAB* stacking arrangement. Syntheses of CuII 3TeVIO6 showed that low-temperature (473 K) hydrothermal conditions generally produce the 2O polytype. XRPD measurements in combination with Raman spectroscopic analysis showed that most natural mcalpineite is the orthorhombic 2O polytype. Both XRPD and Raman spectroscopy measurements may be used to differentiate between the two polytypes of CuII 3TeVIO6. In Raman spectroscopy, CuII 3TeVIO6-1C has a single strong band around 730 cm−1, whereas CuII 3TeVIO6-2O shows a broad double maximum with bands centred around 692 and 742 cm−1.

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Section: Introductionmentioning

confidence: 99%

Polytypism in mcalpineite: a study of natural and synthetic Cu₃TeO₆

Missen¹,

Mills²,

Canossa³

et al. 2022

Acta Crystallogr B Struct Sci Cryst Eng Mater

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“…The only new Te minerals previously described in Australia were three rare tellurides found in Western Australia; namely honeaite (Au 3 TlTe 2 ; Rice et al , 2016; Welch et al , 2017), kalgoorlieite (As 2 Te 3 ; Rempel and Stanley, 2016) and saddlebackite (Pb 2 Bi 2 Te 2 S 3 ; Clarke, 1997). Wortupaite thus represents the first tellurium oxysalt mineral to be described from Australia, and just the sixth new mineral in the Southern Hemisphere after brumadoite from Pedra Preta Pit, Bahia, Brazil (Atencio et al , 2008) and four minerals from the Tambo mine, Coquimbo, Chile: walfordite (Back et al , 1999), telluromandarinoite (Back et al , 2017), and tamboite and metatamboite (Cooper et al , 2019).…”

Section: Introductionmentioning

confidence: 99%

Crystal chemistry of zemannite-type structures: IV. Wortupaite, the first new tellurium oxysalt mineral described from an Australian locality

Missen,

Mills,

Brugger

et al. 2023

MinMag

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Wortupaite (IMA2022–107) is a new hydrated magnesium nickel tellurite mineral with a zemannite-like structure, described from the Wortupa gold mine, South Australia, Australia. Wortupaite forms needles up to 25 μm in length, generally clustered and sometimes in blocky masses of shorter (10‒15 μm) crystals. Wortupaite is found growing on melonite, from which the component nickel and tellurium are derived, and is associated with calcite. The strongest powder diffraction lines are [dobsÅ(Iobs)(hkl)]: 8.059 (93) (100), 4.034 (92) (200), 2.832 (43) (211 and 121), 2.769 (100) (202) and 1.920 (45) (213 and 123). The empirical formula of wortupaite as determined by electron probe microanalysis is (Mg0.57Ni0.39Mn0.04)Σ1(Ni2+1.87Fe3+0.13)Σ2(Te4+O3)3⋅3H2O, simplified to the ideal formula of MgNi2+2(Te4+O3)3⋅3H2O with H2O content calculated from the crystal structure. The average crystal structure of wortupaite was determined by single-crystal X-ray diffraction with synchrotron radiation (R1 = 0.0558 for 100 independent reflections). Wortupaite is hexagonal, crystallising in the space group P63/m, with a = 9.2215(13) Å, c = 7.5150(15) Å, V = 553.43(19) Å3 and Z = 2. Wortupaite has a microporous structure, with the negatively charged zemannite-like framework formed by Te4+O3 trigonal pyramids and Ni2+O6 octahedra. For charge balance, Mg2+ and Ni2+ dominant sites are assumed to be located on central sites in the channels, coordinated by 6 H2O groups. An OW site was refined around the Mg2+ dominant site, but OW position(s) were not locatable around the Ni2+ dominant site. A discussion of the different models for crystallographic arrangement of channel species is provided, taking into account possible Fourier truncation effects. Unlike the other four minerals with zemannite-like structures which have a near 50% split of divalent and trivalent framework cations, wortupaite is the first natural phase to have only divalent cations in the framework sites.

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The discovery of new mineral species and type minerals from Brazil

Atencio

2015

Braz. J. Geol.

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RESUMO:Os minerais foram vistos apenas como fontes de produtos químicos: minério de ferro, minério de cobre, etc. No entanto, não são apenas associações de elementos químicos, uma vez que apresentam estruturas cristalinas. Essas duas características em conjunto proporcionam propriedades que podem ser tecnologicamente úteis. Mesmo que um mineral ocorra em quantidade muito pequena, o que não permite a sua extração, pode servir como um modelo para a obtenção do análogo sintético em uma escala industrial. É necessário que uma proposta de novo mineral seja submetida à aprovação pela Comissão de Novos Minerais, Nomenclatura e Classificação (CNMNC) da Associação Mineralógica Internacional (IMA) antes da publicação. Somente 65 espécies minerais válidas foram descritas pela primeira vez no Brasil, isto é, minerais-tipo do Brasil. Dezenove delas foram publicadas entre 1789 e 1959 (0,11 por ano). De 1959, quando a CNMMN (hoje CNMNC) -IMA foi criada, até 2000, 18 espécies minerais brasileiras aprovadas permanecem válidas (0,43 por ano). No entanto, o número de minerais-tipo do Brasil aprovados nos últimos 15 anos (2000 -2014) foi substancialmente maior: 28 (1,87 por ano). Esse número é muito pequeno considerando a grande variedade de ambientes geológicos brasileiros. As duas primeiras espécies-tipo do Brasil, descobertas no século 18, crisoberilo e euclásio, são importantes minerais gemológicos. Dois outros minerais-gema, membros do supergrupo da turmalina, foram publicados apenas no século 21: uvita e fluor-elbaíta. Alguns minerais-tipo do Brasil são muito importantes tecnologicamente falando. Alguns exemplos são menezesita, coutinhoíta, lindbergita, pauloabibita e waimirita-(Y). menezesite, coutinhoite, lindbergite, pauloabibite, and waimirite-(Y). PALAVRAS-CHAVES:

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Brumadoite, a new copper tellurate hydrate, from Brumado, Bahia, Brazil

Cited by 3 publications

References 4 publications

Polytypism in mcalpineite: a study of natural and synthetic Cu₃TeO₆

Polytypism in mcalpineite: a study of natural and synthetic Cu₃TeO₆

Crystal chemistry of zemannite-type structures: IV. Wortupaite, the first new tellurium oxysalt mineral described from an Australian locality

The discovery of new mineral species and type minerals from Brazil

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Brumadoite, a new copper tellurate hydrate, from Brumado, Bahia, Brazil

Cited by 3 publications

References 4 publications

Polytypism in mcalpineite: a study of natural and synthetic Cu3TeO6

Polytypism in mcalpineite: a study of natural and synthetic Cu3TeO6

Crystal chemistry of zemannite-type structures: IV. Wortupaite, the first new tellurium oxysalt mineral described from an Australian locality

The discovery of new mineral species and type minerals from Brazil

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Product

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Polytypism in mcalpineite: a study of natural and synthetic Cu₃TeO₆

Polytypism in mcalpineite: a study of natural and synthetic Cu₃TeO₆