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DIVISION OF EARTH SCIENCESCollections | Staff Earth Sciences STAFFName: Neville S Pledge BSc. (Hons) Adelaide , MSc. (Wyoming) Position: Honorary Palaeontologist Field work experience: Professional experience: Research programs: Recent publications: Pledge, N.S. (1994 ) Cetacean fossils from the Lower Oligocene of South Australia. Records of the South Australian Museum 27(2):117-124. Pledge, N.S., Archer, M., Hand, S. and Godthelp, H. (1999) Additions to knowledge about ektopodontids (Marsupialia, Ektopodontidae): a new species Ektopodon lithophus. Records of the Western Australian Museum, Supplement 57. Research associates: Dr. R.T.Wells (Flinders University) - Pleistocene marsupials. Name: Dr Allan Pring BSc (Hons) Monash, PhD Cambridge Position: Principal Curator of Minerals Affiliated Associated Professor, Department of Geology and Geophysics, University of Adelaide Adjunct Associate Professor, School of Chemistry, Flinders University Professional experience: 1983-1984 Postdoctoral research fellow, Research School of Chemistry, Australian National University 1984-1988 Curator of minerals, South Australian Museum 1988-1995 Senior Curator of minerals, South Australian Museum 1993 Alexander von Humboldt Research Fellow, Institute of Inorganic and Applied Chemistry, University of Hamburg 1995-present Principal Curator of minerals, South Australian Museum 1989-1999, Visiting lecturer, Dept of Geology, University of Adelaide 1999-2000 Visiting Fellow Commoner, Trinity College, Cambridge Research programs: Structure and composition of sulphide minerals Sulphides are the most important group of ore minerals in many base metal deposits. The relationship between the crystal chemistry of sulphides and their physical, optical and magnetic properties is very different to those of the rock forming minerals. These difference are, in large part, due to the nature of the sulphide ion and the much higher mobility of metal ions in these minerals. This means that significant atomic diffusion persists to much lower temperatures and that processes such as cation ordering and exsolution can occur at measurable rates below 300 °C. In the broad area of sulphide mineralogy we currently have a number of specific research projects. Kinetics of exsolution and cation ordering in the pentlandite-pyrrhotite system. These minerals are the principal ores of nickel in most nickel sulphide deposits. A detailed study of the kinetics of this system using powder neutron diffraction, electron diffraction and minerals synthesis in collaboration with Dr Barbara Etschmann (SA Museum), Prof Andrew Putnis (Uni Münster http://www.uni-muenster.de/Mineralogie/allgemein-englisch/indexframe-english.html), Dr Ben Grguric (WMR) and Dr Andrew Studer (ANSTO). The exsolution of pentlandite from mss/pyrrhotite is rapid at all temperatures above 100 °C, although the rate constant is sensitive to S fugacity and impurity levels.
Kinetics of the transformation of pentlandite to violarite. The transformation of pentlandite (Ni,Fe)9S8 to violarite ((Ni,Fe)3S4 occurs in the supergene zone of many Ni sulphide deposits. It is believed that the transformation involves dissolution and precipitation from low temperature hydrothermal fluids. We will be studying this problem via in situ powder neutron diffraction, using a specially constructed hydrothermal cell which is currently being developed. The project is being undertaken in collaboration with with Dr Barbara Etschmann (SA Museum), Dr Joel Burgger (SA Museum/Uni Adelaide), Mr Haipeng Wang (Ph.D.), Dr Yung Ngothia (Uni Adelaide) Prof Andrew Putnis (Uni Münster), Dr Ben Grguric (WMR) and Dr Andrew Studer (ANSTO). The project will run from 2003-2005 and is funded by the ARC and the DGF. The relationship between stacking order/disorder and composition
in sulphosalt minerals. For non-experts in the field this proposal has, as its background, the concept of polysomatism which can be used to describe the relationship between structures based on the ordered stacking of two or more structurally and stoichiometrically distinct types of units or modules. It is possible to generate a family of mineral structures based on the ordered intergrowth of two different structural modules. High resolution transmission electron microscope studies of these and other polysomatic series have revealed that, in general, the intergrowth structures are well ordered, although mistakes in the stacking sequence have been observed in nearly all polysomatic series. Sulphosalt mineral systems exhibit “pathologically disordered” crystals with seemingly highly disorganised or even random sequences of modules have been found. In the sulphide systems, where significant atomic diffusion persists at much lower temperatures, it is possible that these disordered intergrowths could be more stable and represent a long-range chemical modulation, or compositional waves within the crystals. Over the last few years we have been using high resolution transmission electron microscopy to study structural disorder in three groups of complex bismuth sulphides: the lillianite group, the bismuthinite-aikinite series and the curobismutite group. This work is be undertaken in collaboration with Dr CristianaCiobanu and Dr Nigel Cook (Norwegian Geological Survey)
Subsitutional strain in sulphide solid solutions The concept of the solid solution, in which atoms of one element appear to randomly substitute for those of another in an otherwise essentially invariant crystal structure over an often quite considerable composition range, is a central idea in both solid state chemistry and mineralogy. This form of (approximately) isostructural substitution is at the core of geochemistry and mineralogy and underpins the economic basis of many ores and much of petrology. Simple isovalent substitutions such as Mg/Fe2+, for example, occur in many rock-forming silicates such as olivines, pyroxenes and amphiboles. The substitution of Fe2+ for Zn in sphalerite (ZnS) affects not only the Zn grades of ores, but also their flotation properties and, hence, is of great economic significance. Ideal solid solutions are ones in which these substitutions are truly random and the enthalpy of mixing is zero. Solid solutions are almost never ideal, however, because the substitution of one atom for another necessarily involves the introduction of atoms with different electron configurations and different effective crystal radii. This invariably introduces some form of strain into the lattice. In most cases a high temperature solid solution will thus evolve during cooling via some form of ordering or exsolution. Diffraction evidence for such ordering, particularly if it is not particularly long ranged, is weak, difficult to obtain and often difficult to interpret. Two models for treating the composition dependence of ordering are in common use: the Landau and the generalized Bragg-Williams models. Both approaches are successful at a macroscopic level in many common rock-forming (silicate) mineral systems. The models are rather less successful for modelling order/disorder in sulphide solid solutions and in complex solid solutions involving simultaneous substitution of both anions and cations. This may be largely because the microscopic behaviour of such systems has not yet been investigated experimentally in any detail. In this project we aim to investigate the nature of substitutions in several such solid solution systems at the microscopic level using a variety of techniques, including X-ray charge density mapping, autocorrelation analysis of line broadening in vibrational spectra and via diffuse scattering measurements (TEM and single crystal X-ray diffraction). This project is being undertaken in collaboration with Dr Ray Withers and Prof Richard Welbury (ANU) and Prof Nobuo Ishizawa (Tokyo Institute of Technology). Biomineralization The iridescence colours of pearls and their shells have been ascribed to either interference and or diffraction. While the diffraction component is well established to account for the multicoloured iridescent colour component in shells , the origin of the changes in body colour from pearl to pearl has not been clearly established. Pearls consist of nacre, tiles of aragonite held together by structural proteins, usually overlayed on a shell bead nucleus. Pearls formed by the pearl oysters Pinctada maxima and Pinctada margartifera, often marketed as ‘South Sea Pearls’, have a range of specular body colours including black, silver, cream, yellow and gold of which the black, silver and gold colours are most in demand as jewellery. With P. maxima, the colours include the a range of silver tones, creams. yellows and gold which is most valuable and least common. In P. margartifera, the black pearl oyster, deep black and black silvery tones are important. These colours are also evident in the lips of the shell, which gives rise to the common names silver lip, gold lip and black lip oysters. In addition the pearls can display an orient or colour play usually more evident on the insides of their shells that has recently been shown to arise from diffraction by regular surface features formed by plate growth terminating on the surface. A further complication is the existenance of so called blue pearls, commonly with a leaden grey colour, which posses bands of dark organic matter known as conchiolin giving the pearl a dark appearance.1 The evidence we present here establishes that the iridesence primary body colour of pearls arises by the interference of light in the binding regions of the plates. The plate faces terminate in a fissured structure anchoring the bonding proteins and gives rise to complex optical cavity. The TEM pictures show that the cavity width increases from less than 62nm wide in a silver pearl to 80nm in a cream pearl and to 105nm in a gold pearl. The colours are the first order Newton’s colours which when mixed with the specular reflection of the nacre and darkened by any conchiolin component gives rise to the body colour of pearls. This project is being undertaken in collaboration with Dr Mike Snow (SA Museum) and Dr Peter Self (Adelaide University.) Mineral Taxonomy Few scientists and politicians today would question the importance of studying and preserving the biological diversity of the planet. In fact, a new word, biodiversity, has entered our language and in 1992 the World's leaders gathered in Rio de Janeiro to sign a convention aimed at ensuring that the Earth's biological diversity is studied and preserved. Much has been said and written about the importance of rainforests and their diversity, but have you ever heard anything about the importance of studying mineralogical diversity. A major part of winning public support for the study, preservation and documentation of mineral diversity is the need to present ideas which they can readily relate to. In 1995 the term mineralogical rainforest was introduced to describe mineralogically very diverse deposits (Pring, Aust. J. Mineral. 1, (2) 3-7 1995) There are some 4000 known species of minerals and maybe 10000 in total. Approximately 50 new mineral species are described each year. Many of these new species occur only as tiny grains or in very small quantities and are generally not of great importance in rock-forming processes. Thus they are not of great interest to the majority of geologists. A few deposits have incredible but highly localized diversity. These mineralogical rainforests are where the Earth's geochemistry is at its most complex and by studying the stabilities of the various minerals and their associations it is possible to gain a very detailed history of each deposit’s formation and subsequent history. More often than not these deposits are associated with lead-zinc ± copper mineralisation. The list of deposits from which 250 minerals or more are known includes the Franklin-Sterling Hill deposits in New Jersey; Tsumeb, Namibia; the Clara Mine in the Black Forest, Germany; Broken Hill, New South Wales and Långban, Sweden. The alkaline intrusion at Mont Saint-Hiliare, Canada has also produced around 250 species while similar intrusions at Ilimaussaq have produced nearly 200 species. The alkaline intrusions of the Kola Peninusla as a group have produced approximately 500 minerals, while a number individual intrusions have in excess of 250 species. All of these mineralogical rainforests have one other factor in come; they have all been studied in great detail by mineralogists. There are probably many such deposits but they await the attention of collectors and scientist. Only through publishing our ideas in the popular scientific media can we hope to enlist public support for the preservation of mineral diversity. A major part of our brief at the South Australian Museum is to document the mineralogy of the State. We use a wide variety of experimental techniques to characterize both new species and new records for the State. We are currently working on a new mineralogy of South Australia which will appear both in the Web and in book form. This work is undertaken in collaboration with Dr Joel Brugger (SA Museum/Uni Adelaide), Peter Elliot and members of the Mineralogical Society of South Australia. Selected Recent publications: Books Mineralogy for Students by M.H. Battey and A. Pring Papers Birch, W.D., Pring, A., Reller, A., and Schmalle, H. Bernalite: a new ferric hydroxide with perovskite structure Naturwissenschaften, 79, 509-511 1992. Pring, A., Williams, T.B. and Withers R.L. Structural modulation in sartorite: an electron microscope study. American Mineralogist, 78, 619-626, 1993. Birch, W.D., Pring, A., Reller, A., and Schmalle, H. Bernalite, Fe(OH)3, a new mineral from Broken Hill, New South Wales: Description and structure. American Mineralogist, 78, 827-834, 1993. Pring, A. and Graeser, S. (1994) Polytypism in baumhauerite. American Mineralogist, 79, 302-307, 1994. Pring, A., Birch, W.D., Dawe, J., Taylor, M., Deliens, M., and Walenta, K. Kintorite, PbFe3(PO4)2(OH,H2O)6, a new mineral of the jarosite-alunite family and lusingite discredited. Mineralogical Magazine, 59, 143-148 1995. McCammon, C.A., Pring, A. Keppler, H., and Sharp, T. A.study of bernalite Fe(OH)3, using Mšssbauer spectroscopy, optical spectroscopy and transmission electron microscopy. Physics and Chemistry of Minerals, 22, 11-20, 1995. Pring, A. Annealing of synthetic hammarite, Cu2Pb2Bi4S9, and the nature of cation ordering processes in the bismuthinite-aikinite series. American Mineralogist, 80, 1168-1175 1995. Kharisun, Taylor, M., Bevan, D.J.M, and Pring, A. The crystal structure
of kintoreite PbFe3(PO4)2(OH,H2O)6.
Mineralogical Magazine, 61, 123-129,
1997. Kharisun, Taylor, M., Bevan, D.J.M, and Pring, A.The crystal chemistry of duftite, PbCuAsO4(OH) and the b-duftite problem. Mineralogical Magazine, 61, 121-130, 1998. Birch, W.D., Pring, A., Gatehouse, B.M. and McCammon, C. A. Bamfordite a new hydrated ferric molybdate from Bamford, Queensland. Description and crystal structure. American Mineralogist, 83, 172-177, 1998. Pring, A. Selenides and Sulfides from Iron Monarch, South Australia. Neues Jahrbuch für Mineralogie Monatsheft, 36-48 1998. Jercher, M., Pring, A., Jones, P.G., and Raven, M.D. Rietveld X-ray diffraction and X-ray fluorescence analysis of Australian Aboriginal Ochres. Archaeometry, 40, 383-401. 1998. Pring, A. Grguric, B and Criddle, A. Lindströmite from Cobalt, Ontario, Canada. Canadian Mineralogist, 36, 1139-48 1998. Kolitsch, U., Slade, P., Tiekink, E. and Pring, A. The structure of antimonian dussertite and the role of antimony in oxysalt minerals. Mineralogical Magazine, 63, 17-26, 1999. Kolitsch, U., Tiekinik, E.R., Slade, P.G., Taylor, M.R. and Pring, A. Hindsdalite and plumbogummite, their atomic arrangement and disordered lead sites. European Journal of Mineralogy, 11, 513-520, 1999. Pring, A., Kolitsch, U., Birch, W.D., Beyer, B.D., Elliott, P, Ayyappan, P. and Ramanan, A. Bariosincosite, a new hydrated barium vanadium phosphate from the Spring Creek Mine, South Australia. Mineralogical Magazine, 63, 735-741, 1999. Koltisch, U., Pring, A., Taylor, M.R. and Fallon, G. Springcreekite BaV3+3(PO4)2(OH,H2O)6, a new member of the crandallite group from the Spring Creek Mine, South Australia: the first natural V3+ member of the alunite family and its crystal structure. Neues Jahrbuch für Mineralogie Monatsheft 529-544, 1999. Birch, W.D., Pring, A. and Kolitsch, U. Bleasdaleite, a new mineral from Lake Boga, Victoria, Australia. Australian Journal of Mineralogy, 5, 69-75, 1999. Koltisch, U., Pring, A., and Elliott, P. An update on the mineralogy of the Spring Creek Mine, South Australia, including the new species springcreekite, bariosincosite and johntomaite. Australian Journal of Mineralogy, 5, 55-62, 1999. Pring, A., Jercher, M. and Makovicky, E. Disorder and compositional variation in the lillianite homologous series. Mineralogical Magazine, 63, 917-926, 1999. Kolitsch, U. and Pring, A. and Tiekink, E. Johntomaite, a new member of the bjarebyite group from the Spring creek Mine. Mineralogy and Petrology, 70, 1-14, 2000. Pring, A. Kolitsch, U and Francis, G. Additions to the Mineralogy of the Iron Monarch Deposit, Middleback Ranges, South Australia. Australian Journal of Mineralogy, 6, 9-23, 2000 Pring, A., T. The crystal chemistry of the sartorite group minerals from Lengenbach, Binntal, Switzerland: A HRTEM study. Schweizerische Mineralogische und Petrographische Mitteilungen. 81, 69-87, 2001. Kolitsch, U and Pring, A. Crystal chemistry of the crandallite, beudantite and alunite groups; a review and evaluation of the suitability as storage materials for toxic metals. Journal of Mineralogy and Petrological Sciences. 96, 67-78, 2001. Grguric. B.A., Madsen, I.C. and Pring, A. Woodallite, a new chromium analogue of iowaite from the Mount Keith nickel deposit, Western Australia. Mineralogical Magazine. 65, 421-429, 2001. Pring, A. and Etschmann, B. Crystal chemistry of cosalite, and its relationship to the lillianite group. Mineralogical Magazine, 66, 451-458, 2002. Wallwork, K.S., Kolitsch, U., Pring, A. and Nasdala, L. Decrespignyite-(Y), a new copper yttrium rare earth carbonate chloride hydrate from Paratoo, South Australia. Mineralogical Magazine, 66, 165-172, 2002. Wallwork, K.S., Pring A., Taylor, M.R. and Hunter, B.A. Structure solution of priceite, a basic hydrated calcium borate, by ab initio powder-diffraction methods. Canadian Mineralogist, 40, 1199-1206, 2002 Birch, W.D., Pring, A. and Wallwork, K. (2002) Mendozavilite from the Fitzgreald River district, Western Australia. Australian Journal of Mineralogy, 8, 11-15. 2002 Wallwork, K.S., Pring A., Taylor, M.R. and Hunter, B.A. Structure solution of the hydrated aluminum phosphate, kingite by ab initio powder diffraction methods. American Mineralogist. 88, 235-239, 2003 Notes and Minor Publications Pring, A. The place of descriptive mineralogy in modern science. Australian Journal of Mineralogy. 1, (No 2), 3-7. 1995 Pring, A. Mineral Diversity and Modern Science. The Australian Geologist No 98, 56-58. 1996
Pring, A. The Mineralogical collection of the South Australian Museum, Adelaide. Australian Journal of Mineralogy, 6, 59-70 2000. Pring, A. Hidden Treasure Revealed. MESA Journal 19 32-33. 2000. Sutherland, L.F., Pogson, R.E., Birch, W.D., Henry, D.A., Pring, A., Bevan, A.W.R., Stalder, H.A. and Graham, I.T. Mineral species first described from Australia and their type specimens. Australian Journal of Mineralogy. 6, 105-129, 2000. Pring, A Cecil Edgar Tilley, Australian Dictionary of Biography, 16, 396-397, 2002 Name: Brendan (Ben) J. McHenry BSc. (Hons)
Melbourne, MSc Adelaide Position: Collections Manager, Earth Sciences Field work experience: Professional experience: Research/interest programs: Recent publications: Students: Name: James A. McNamara Bsc. (Hons) Adelaide Position: Collection Manager, Vertebrate fossils Please note that, Australian Plants Online replaces, http://www.samuseum.sa.gov.au/mundulla_yellows.pdf or full text in word.doc available from Jim McNamara. Field work experience: Research/interest programs: Recent publications:
McNamara, J.A. (1997) Some Smaller macropod fossils of South Australia. Proc. Linn.Soc N.S.W., 117:97-106. |
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Structure
and colour of Pearls