The crystal structure of waylandite from Wheal Remfry, Cornwall, United Kingdom

Mills, Stuart J.; Kampf, Anthony R.; Raudsepp, Mati; Birch, William D.

doi:10.1007/s00710-010-0133-7

Cited by 8 publications

(4 citation statements)

References 19 publications

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“…But it is the discovery of jarosite on Mars (Klingelhöfer et al 2004;Farrand et al 2009) in particular that has caused a renaissance in research about the formation and stability of the mineral (e.g., Navrotsky et al 2005;Papike et al 2006;Golden et al 2008) and its structural analogues (e.g., Grey et al 2008Grey et al , 2009Grey et al , 2011Grey et al , 2013Mills et al 2010;Scarlett et al 2010Scarlett et al , 2013. Despite this, very few single-crystal refinements of jarosite have been made, and none at low temperature.…”

mentioning

confidence: 95%

Looking for jarosite on Mars: The low-temperature crystal structure of jarosite

Mills

Nestola

Kahlenberg

et al. 2013

American Mineralogist

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Single-crystal diffraction of jarosite, KFe 3 3+ (SO 4 ) 2 (OH) 6 , has been undertaken at low temperatures that proxy for martian surface conditions. Room-temperature data are consistent with literature data [a = 7.2913(5), c = 17.1744 (17), and V = 790.72 (11) in R3m], while the first low-temperature data for the mineral is presented (at 253, 213, 173, and 133 K). Data collections between 297 and 133 K show strongly anisotropic thermal expansion, with the c axis much more expandable than the a axis. Much of the anisotropy is due to strong distortion of the KO 12 polyhedron, which increases by 8% between 297 and 133 K. The data sets can aid in the identification of jarosite by X-ray diffraction of martian soils using the Curiosity Rover's CheMin instrument.

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mentioning

confidence: 95%

Looking for jarosite on Mars: The low-temperature crystal structure of jarosite

Mills

Nestola

Kahlenberg

et al. 2013

American Mineralogist

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“…Furthermore, Bi in alunite-supergroup minerals occurs rarely and there are only two known Bi-dominant end-members: waylandite BiAl 3 (PO 4 ) 2 (OH) 6 (von Knorring and Mrose, 1963; Clark et al , 1986; Mills et al , 2010; Uehara and Shirose, 2013); and zaïrite, BiFe 3 (PO 4 ) 2 (OH) 6 (Van Wambeke, 1975). The arsenate-analogue of waylandite is described incompletely by Scharm et al (1994) as ‘arsenowaylandite’ and is questionable because of inadequate data.…”

Section: Discussionmentioning

confidence: 99%

“…The acidic conditions and sizeable As supply during the initial acidic stage created conditions conducive for the precipitation of the alunitesupergroup mineral phases. Philipsbornite is a stable phase under acidic conditions (pH < 4; Leverett et al, 2003) and segnitite could be synthesised by hydrothermal methods in the pH range 1.0-1.5 (Mills, 2007). Furthermore, Sb-rich segnitite from Black Pine Mine, Montana, USA appears to have formed under oxidising conditions and pH < 2 (Mills et al, 2014).…”

Section: Evolution Of the Oxidation Zone And Formation Of Supergene M...mentioning

confidence: 99%

Secondary uranyl arsenates–phosphates and Sb–Bi-rich minerals of the segnitite–philipsbornite series in the oxidation zone at the Prakovce-Zimná Voda REE–U–Au quartz-vein mineralisation, Western Carpathians, Slovakia

Ondrejka,

Ferenc,

Majzlan

et al. 2023

MinMag

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This work is an investigation of the assemblages of supergene minerals occurring in hydrothermal REE–U–Au quartz-vein mineralisation at the Prakovce-Zimná Voda site, Slovakia. Heterogeneous uranyl arsenates and minor phosphates of the autunite group (nováčekite, kahlerite, threadgoldite, autunite, arsenuranospathite and chistyakovaite) together with scorodite and Sb–Bi-rich philipsbornite–segnitite-series minerals formed by oxidising fluids during decomposition and leaching of primary hypogene uraninite, brannerite and base-metal sulfides and sulfosalts. A progressive change of pH from acidic to near-neutral due to the gradual consumption of sulfides resulted in the formation of late phosphuranylite, pharmacosiderite and arseniosiderite. Goethite and other Fe oxides represent the latest hydrous ferric mineral phases and were formed after most of the As was already fixed in Fe arsenates. Antimony and Bi were taken up only into philipsbornite–segnitite and suggest unusual conditions during this process. X-ray absorption spectroscopy indicates that Sb in the philipsbornite–segnitite is fully oxidised (0.1–0.4 apfu Sb5+, octahedral coordination on the G site). Pentavalent Sb together with the presence of ferric oxides and arsenates and uranyl minerals suggest oxidative conditions during weathering. This study also indicates that hydrous ferric arsenates are dominant and stable secondary minerals in a supergene environment in a quartz vein rich in Fe and As accompanied by elevated concentrations of U, Pb, Sb, Bi, S, P, Ca and Ba under oxidising conditions.

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“…Phosphates of the alunite supergroup are an extensive class of inorganic compounds with the AB 3 (PO 4 ) 2 (OH) 6 chemical formula, where A is Ce, La, Nb, Sm, Ca, Sr, Pb, Ba, Bi, and B is Al, Fe, V; they are similar in their structural parameters, syngony (trigonal/hexagonal), space group (R3m), and represent crystals with the hexagonal scalenohedron geometry [4][5][6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Thermal stability of the waylandite-structured nanocrystalline BiAl3(PO4)2(OH)6

Elovikov¹,

Proskurina²,

Tomkovich³

et al. 2022

Nanosystems: Phys. Chem. Math.

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A nanocrystalline powder of the waylandite-structured bismuth hydroaluminophosphate was obtained under hydrothermal conditions at 200 • C, 7 MPa and pH 7, and characterized by X-ray diffractometry, scanning electron microscopy (SEM), and energy dispersive microanalysis (EDAX). The simultaneous thermal analysis and high-temperature X-ray diffractometry have shown that the crystal-chemical formula of this compound can be represented as BiAl 3 (PO 4 ) 2 O(OH) 4 •(H 2 O). This compound retains its structure and crystallite size (∼65 nm) up to about 500 • C. It has been determined that the decomposition of this compound in the 540-800 • C range results in the formation of Bi 2 O 3 , Bi 2 Al 4 O 9 and AlPO 4 phases. At temperatures above 800 • C, a complete thermal decomposition of Bi 2 Al 4 O 9 and the formation of crystalline α-Al 2 O 3 occur in this system, while Bi 2 O 3 keeps evaporating during the isothermal exposure. KEYWORDS nanocrystals, waylandite-structured, BiAl 3 (PO 4 ) 2 O(OH) 4 •(H 2 O), thermal stability, hydrothermal synthesis, nature-like technologies. ACKNOWLEDGEMENTS X-ray diffraction studies and elemental analyses of samples were performed employing the equipment of the Engineering Center of the

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The crystal structure of waylandite from Wheal Remfry, Cornwall, United Kingdom

Cited by 8 publications

References 19 publications

Looking for jarosite on Mars: The low-temperature crystal structure of jarosite

Looking for jarosite on Mars: The low-temperature crystal structure of jarosite

Secondary uranyl arsenates–phosphates and Sb–Bi-rich minerals of the segnitite–philipsbornite series in the oxidation zone at the Prakovce-Zimná Voda REE–U–Au quartz-vein mineralisation, Western Carpathians, Slovakia

Thermal stability of the waylandite-structured nanocrystalline BiAl3(PO4)2(OH)6

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