Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-28T04:57:59.346Z Has data issue: false hasContentIssue false
  • English
  • Français

Angastonite, CaMgAl2(PO4)2(OH)4·7H2O: a new phosphate mineral from Angaston, South Australia

Published online by Cambridge University Press:  05 July 2018

S. J. Mills ,
L. A. Groat ,
S. A. Wilson ,
W. D. Birch ,
P. S. Whitfield  and
M. Raudsepp
S. J. Mills*
Affiliation:
Department of Earth and Ocean Sciences, University of British Columbia, Vancouver BC, Canada V6T 1Z4
L. A. Groat
Affiliation:
Department of Earth and Ocean Sciences, University of British Columbia, Vancouver BC, Canada V6T 1Z4
S. A. Wilson
Affiliation:
Department of Earth and Ocean Sciences, University of British Columbia, Vancouver BC, Canada V6T 1Z4
W. D. Birch
Affiliation:
Geosciences, Museum Victoria, GPO Box 666, Melbourne Victoria, 3001, Australia
P. S. Whitfield
Affiliation:
Institute for Chemical Process and Environmental Technology, National Research Council of Canada, Montreal Road, Ottawa ON, Canada K1A 0R6
M. Raudsepp
Affiliation:
Department of Earth and Ocean Sciences, University of British Columbia, Vancouver BC, Canada V6T 1Z4
*
*E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Angastonite, ideally CaMgAl2(PO4)2(OH)4-7H2O, is a newly defined mineral from the Penrice marble quarry, South Australia. The mineral occurs as snow-white crusts and coatings up to ∼1 mm thick associated with minyulite, perhamite, crandallite and apatite-(CaF). The streak is white, the lustre is pearly and the estimated hardness is 2 on the Mohs scale. Angastonite forms platy crystals with the forms {010} (prominent), {101}, {101} and {100} (rare), and also occurs as replacements of an unknown pre-existing mineral. There is one cleavage direction on ﹛010} and no twinning has been observed. Angastonite is triclinic, P1̄, with a = 13.303(1) Å, b = 27.020(2) Å, c = 6.1070(7) Å α = 89.64(1)°, β = 83.44(1)°, γ = 80.444(8)°, V = 2150.5(4) Å3, with Z = 6. The mineral is optically biaxial (+), with refractive indices of α = 1.566(2), β = 1.572(2) and γ 1.584(2) and with 2Vmeas = 70(2)° and 2Vcalc = 71°. Orientation: X ≈ a, Y ≈ b, Z ≈ c; with crystals showing parallel extinction and no axial dispersion. Dmeas is 2.47 g/cm3, whilst Dcalc is 2.332 g/cm3. The strongest four powder-diffraction lines [d in Å, (I/I°), hkl] are: 13.38, (100), 020; 11.05, (25), 11̄0; 5.73, (23), 101, 230 and 111; 8.01, (21), 130. Angastonite is likely to be related to the montgomeryite-group members and have a similar crystal structure, based on slabs of phosphate tetrahedra and Al octahedra.

Keywords

angastonitenew mineralPenrice marble quarryAngastonSouth Australiamontgomeryiteperhamite
Type
Research Article
Information
Mineralogical Magazine , Volume 72 , Issue 5 , October 2008 , pp. 1011 - 1020
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anthony, J.W., Bideaux, R.A., Bladh, K.W. and Nichols, M.C. (2000) Handbook of Mineralogy, Volume IV. Arsenates, Phosphates, Vanadates. Mineral Data Publishing, Tucson, AZ, USA. 680 pp.Google Scholar
Benbow, M.C., Callen, R.A., Bourman, R.P. and Alley, N.F. (1995) Deep weathering, ferricrete and silcrete. Pp. 201–207 in: The Geology of South Australia, vol. 2, The Phanerozoic (Drexel, J.F., and Preiss, W.V., editors), Bulletin 54, Geological Survey of South Australia.Google Scholar
Bruker, AXS (2008) TOPAS, V4.1, Bruker AXS, Karlsruhe, Germany.Google Scholar
Burke, E.A.J. (2008) Tidying up mineral names: an IMACNMNC scheme for suffixes, hyphens and diacritical marks. Mineralogical Record, 39, 131–135.Google Scholar
Drexel, J.F. and Preiss, W.V. (editors) (1995) The Geology of South Australia, vol. 2, The Phanerozoic, Bulletin 54, Geological Survey of South Australia.Google Scholar
Harrowfield, J.R., Segnit, E.R. and Watts, J.A. (1981) Aldermanite, a new magnesium aluminium phosphate. Mineralogical Magazine, 44, 59–62.CrossRefGoogle Scholar
Jack, R.L. (1919) The phosphate deposits of South Australia. Bulletin 7, Geological Survey of South Australia.Google Scholar
Johns, R.K. (1962) South Australian rock phosphate deposits. Mining Review Adelaide, 114, 22–30.Google Scholar
Jones, J.B. (1983) Phosphate deposits of the Mount Lofty and Middleback Ranges. In. Phosphate occurrences in Australia, Abstract volume. The Mineralogical Societies of New South Wales, South Australia and Victoria, Annual Seminar, Adelaide, Australia.Google Scholar
Mandarino, J.A. (1981) The Gladstone-Dale relationship: Part IV. The compatibility concept and its application. The Canadian Mineralogist, 19, 441–450.Google Scholar
Mills, S.J. (2003) A note on perhamite from the Moeulta (Klemms) phosphate quarry, South Australia. Australian Journal of Mineralogy, 9, 43–45.Google Scholar
Mills, S.J., Grey, I.E., Mumme, W.G. and Bordet, P. (2006) The crystal structure of perhamite. Mineralogical Magazine, 70, 201–209.CrossRefGoogle Scholar
Moore, P.B. and Araki, T. (1974) Montgomeryite, Ca4Mg(H2O)12[Al4(OH)4(PO4)6]: its crystal structure and relation to vauxite, Fe2+(H2O)4[A14(OH)4(H2O)4(PO)4]4H2O. American Mineralogist, 59, 843–850.Google Scholar
Pilkington, E.S., Segnit, E.R. and Watts, J.A. (1982) Peisleyite, a new sodium aluminium sulphate phosphate. Mineralogical Magazine, 46, 449–452.CrossRefGoogle Scholar
Sauer, G.R., Zunic, W.B., Durig, J.R. and Wuthier, R.E. (1994) Fourier transform Raman spectroscopy of synthetic and biological calcium phosphates. Calcified Tissue International, 54, 414–420.CrossRefGoogle ScholarPubMed
Segnit, E.R. and Watts, J.A. (1981) Mineralogy of the rock phosphate deposit at Moeulta, South Australia. Australian Mineralogist, 35, 179–186.Google Scholar
Sheard, M.J. and Smith, P.C. (1995) Karst and mound spring deposits. Pp. 257–261 in: The Geology of South Australia, vol. 2, The Phanerozoic, (Drexel, J.F. and Preiss, W.V., editors), Bulletin 54, Geological Survey of South Australia.Google Scholar