Dr Andrew Christy

Lecturer in Mineralogy/Sen Curator

School of Earth and Environmental Sciences
Faculty of Science
a.christy@uq.edu.au
+61 7 336 51540

Overview

BA(Hons) and PhD from the Department of Earth Sciences, Cambridge, UK. My PhD project on the mineral sapphirine made much use of X-ray diffraction, electron microscopy and electron microprobe analysis, experimental techniques which I still use today, as well as enduring fascinations with (i) minerals and mineral assemblages that form at extremely high pressures and/or temperatures and (ii) crystal structures that are assembled out of layer-, rod- or block-like modules that can fit together in more than one way (modular structures), producing a range of different well-ordered arrangements, disordered arrangements, and those in between, depending on pressure, temperature, chemical composition and crystal growth conditions. Afterwards, I spent a couple of years working in the very different world of precipitation and dissolution from saline brines at relatively low pressures and temperatures, before moving to the Chemistry Department at Leicester University (UK), where I returned to the study of crystal structure transformations under the extreme pressures that can be obtained in a diamond anvil cell (as well as designing a prototype high-temperature diaond anvil cell). In order to get information out of tiny samples contained in their diamond-and-metal containers, I became a heavy user of a synchrotron X-ray beamline at the former Daresbury Laboratory in northwest England.

In 1994, I moved to Australia, to take up a Research Fellowship the Research School of Chemistry at the Australian National University, Canberra, studying short-range ordering in disordered crystals using diffuse X-ray scattering and computer simulation. Between then and 2016, I held a range of other positions around the ANU campus: writing image-processing software in the Forestry Dept; a second Research Fellowship in the Research School of Physics & Engineering, studying the self-organised microfossil-like nanocomposite materials called 'biomorphs'; managing a suite of analytical labs and lecturing in mineralogy in the former Geology Dept, and a senior lectureship developing an education program for the Centre for Advanced Microscopy.

I arrived in Brisbane in October 2016 as one of two new joint positions between the Queensland Museum and the University of Queensland,as a senior curator at QM and lecturer in mineralogy at UQ.

I have been an Associate Editor since 1998 for 'Mineralogical Magazine', the UK-based highest-impact specialist journal for mineralogy, and of 'European Journal of Mineralogy' since 2014. In 2013, I was awarded and Honorary Life Fellowship by the Mineralogical Society of Great Britain and Ireland. I am also a member of the Mineralogical Society of America, and am the representative in the Geological Society of Australia of the International Mineralogical Association (IMA). I have also been since 2007 the Australian national representative on the IMA's Commission for New Minerals, Nomenclature and Classification (CNMNC), and have served on two specialist subcommittees of the CNMNC. I am the Vice-Chair of the Local Organising Committee for the upcoming International Mineralogical Association quadrennial meeting in Melbourne, in August 2018.

Research Interests

  • Microbe-mediated mineralisation
    Example: some cyanobacteria do not initially build microbialites out of the expected calcium carbonate minerals, but instead from magnesium silicates. This occurs in near-neutral waters rather than the highly alkaline volcanic lake environments traditionally assumed to be necessary for Mg silicates, which forces a reinterpretation of the depositional environments for "sedimentary talc" deposits and the South Atlantic Pre-Salt hydrocarbon reservoir. In the latter, silicate-carbonate replacement textures can control permeability and hence hydrocarbon mobility and recovery.
  • Structure, properties and applications of nanominerals
    Many low-temperature secondary minerals have tiny crystals and disordered crystal structures that require a combination of state-of-the-art experimental and theoretical techniques for solution. However, understanding of how chemical elements are structurally accommodated in/on microscopic and submicroscopic crystals may lead to novel methods for resource recovery, as well as development of materials with useful catalytic or sorption properties.
  • Short-range versus long-range order and crystal structure variation in minerals
    In nature, minerals form in a soup of 70 or so chemical elements, and so are rarely pure chemical compounds. Different elements may mix easily in some sites of the crystal structure, or may not. Ordered patterns may persist over macrosocpic distances, or only on the very local scale. Similarly, whole blocks of crystal structure may link together in regularly repeating ways, or less regularly. Such flexibility may have a large effect on the stability and properties of mineral species, but because it involves non-periodic structure, requires an unorthodox mix of techniques to characterise.
  • Mineral diversity, crystal structure systematics and structure-paragenesis relationships.
    Why do some chemical compounds occur as mineral species in nature, but not others? How many can we expect to find, and where should we look for them? Why are some common, but others rare? Why do they have the particular atomic arrangements that they do, and what does this tell us about conditions of formation? New approaches to data analysis are bringing about a resurgence of interest in these basic questions, and providing some partial answers.

Qualifications

  • Doctor of Philosophy, University of Cambridge
  • Bachelor of Arta, University of Cambridge

Publications

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Publications

Featured Publications

Book Chapter

  • Christy, Andrew G. (2018). Sulfate minerals. In William M. White (Ed.), Encyclopedia of Geochemistry (pp. 1392-1394) Dordrecht, Netherlands: Springer Netherlands. doi:10.1007/978-3-319-39312-4_30

  • Fogden, Andrew, Olson, Terri and Christy, Andrew G. (2016). Nanoscale imaging of organic matter and wettability of oil-window shales. In (pp. 25-42) : American Association of Petroleum Geologists. doi:10.1306/13592015M1121402

  • Li, Huijuan, Zhang, Lifei and Christy, Andrew G. (2011). The correlation between Raman spectra and the mineral composition of muscovite and phengite. In Larissa Dobrzhinetskaya, Shah Wali Faryad, Simon Wallis and Simon Cuthbert (Ed.), Ultrahigh-pressure metamorphism (pp. 187-212) Amsterdam, The Netherlands: Elsevier. doi:10.1016/B978-0-12-385144-4.00006-0

  • Rode, A. V., Christy, A. G., Gamaly, E. G., Hyde, S. T. and Luther-Davies, B. (2006). Magnetic Properties of Novel Carbon Allotropes. In Carbon Based Magnetism (pp. 463-482) Amsterdam, Netherlands: Elsevier. doi:10.1016/b978-044451947-4/50021-9

  • Carnerup, Anna M., Hyde, Stephen T., Larsson, Ann-Kristin, Christy, Andrew G. and GarcÍa-Ruiz, Juan Manuel (2004). Silica-Carbonate Biomorphs and the Implications for Identification Of Microfossils. In Life in the Universe (pp. 221-222) Dordrecht: Springer Netherlands. doi:10.1007/978-94-007-1003-0_46

Journal Article

Conference Publication

Grants (Administered at UQ)