Mengeite, Ba(Mg,Mn2+)Mn3+4(PO4)4(OH)4·4H2O, a New Mineral from the Spring Creek Mine, South Australia, Australia
Affiliation:
1. Department of Earth Sciences, School of Physical Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia 2. South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia
Abstract
ABSTRACT
Mengeite, Ba(Mg,Mn2+)Mn3+4(PO4)4(OH)4·4H2O, is a new mineral from the Spring Creek copper mine, near Wilmington, South Australia, Australia, where it occurs as dark orange-red masses to 0.8 mm across in a quartz matrix. The streak is pale salmon pink and the luster is vitreous. Mengeite is non-fluorescent and the Mohs hardness is ∼3. The measured density is 3.40 g/cm3 and the calculated density is 3.43 g/cm3. Mengeite is biaxial (–) with α = 1.757(4), β = 1.776(4), γ = 1.781(4) measured in white light. Electron microprobe analyses results give the empirical formula, based on 24 O apfu: Ba1.09(Mg0.58Mn2+0.26Cu0.10Al0.02Na0.01Ca0.01□0.09)Σ1.07Mn3+3.88(PO4)4.07(OH)3.52·4.13H2O. The idealized formula is Ba(Mg,Mn2+)Mn3+4(PO4)4(OH)4·4H2O. Mengeite is triclinic, space group , with a = 5.4262(11), b = 5.4274(11), c = 16.387(3) Å, α = 87.61(3), β = 98.97(3), γ = 110.56(3)°, V = 446.28(16) Å3, and Z = 1. The crystal structure of mengeite was solved using synchrotron single-crystal X-ray diffraction data and refined to R1 = 0.0453 for 2115 observed reflections with F0 > 4σ(F0). It is based on [(M2(OH)2(AsO4)2] sheets that are linked in the c-direction alternately by [M3(H2O)4O2] octahedra and by BaO10 polyhedra.
Publisher
Mineralogical Association of Canada
Subject
Geochemistry and Petrology
Reference28 articles.
1. Austin,
J.B.
(1863)
The mines of South Australia; including also an account of the smelting works in that colony, together with a brief description of the country and incidents of travel in the bush, by J. B. Austin. Adelaide, C. Platts, E. S. Wigg, G. Dehane, J. Howell, W. C. Rigby, G. Mullett, 1863. Adelaide, 109p. Reprinted by Libraries Board of South Australia, Adelaide. 2. Beyer,
B.D.
&
Elliott,P.
(1996)
Minerals from the Spring Creek mine, near Wilmington, South Australia.
Australian Journal of Mineralogy2,
57–70. 3. Binks,
P.J.
,
Forbes,B.G., &
Mirams,R.C.
(1968)
Orroroo sheet, S 54-1 1:250,000.
Geological Survey of South Australia 4. Callegari,
A.M.
,
Boiocchi,M.,
Ciriotti,M., &
Balestra,C.
(2012)
Coralloite, Mn2+Mn3+2(AsO4)2(OH)2·4H2O, a new mixed valence Mn hydrate arsenate: Crystal structure and relationships with bermanite and whitmoreite mineral groups.
American Mineralogist97,
727–734. 5. Cawthorne,
W.A.
(1859)
Menge the Mineralogist. Adelaide, 33 p.
Reprinted by Public Library of South Australia,
Adelaide.
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