The University of British Columbia

My work covers four main areas of mineralogy: crystal chemistry and mineral physics, granitic pegmatites, environmental mineralogy, and the mineralogy of gemstones.

Crystal Chemistry and Mineral Physics:

• vesuvianite -- one of the principal conclusions of my work has been that some "vesuvianites" contain major amounts of boron; these have recently been redefined as the new mineral wiluite
• borosilicate minerals dumortierite, holtite, and grandidierite -- concentrating primarily on correlations between chemical composition, crystal structure, morphology and conditions of formation
• titanite -- using transmission electron microscopy to study the kinetics of the annealing process in metamict titanite
• amblygonite-montebrasite minerals -- ideal for studying F«OH substitution because natural members of the series show little cation substiution
• oxysalt minerals containing heavy elements (e.g., Te, Ba, Pb, and Hg) -- poorly studied in the past because of analytical problems associated with heavy atoms. Te-oxysalt minerals are very interesting because of the presence of Te4+ (with lone-pair electrons) and/or Te6+. The Hg-oxysalt minerals are worthy of study as a result of the presence Hg+ (in dimers) and/or Hg2+ and because they immobilize Hg (a toxic heavy metal).
• overall study of the influence of chemical composition on physical properties in isostructural compounds.

The Little Nahanni Pegmatite Group: Arguably world's best example of the albite-spodumene class of granitic pegmatites. Our work has shown that the Group is an important potential future source of rare elements such as Li, Nb and Ta. Recently I began research on granitic pegmatites in southeastern British Columbia.

The mineralogy, geology and origin of Canada's first significant emerald deposit, the Crown showing in southeastern Yukon.

Recently I have begun a new project on metamorphic gem minerals of the Slocan Valley.

Environmental Mineralogy: Mineralogy of base metal tailings with a variety of sulfide contents. My objectives are to determine rates of oxidation, to evaluate the validity of laboratory experiments used for the prediction of acid mine drainage potential, and to develop better predictive models. I am also involved in studies of natural acid rock drainage at Limonite Creek in northwestern British Columbia and of mine wastes and neutralization potential.

Geomicrobiology is an important new area of research. In the early `90s I was involved in several bioleaching projects. In order to learn more about the field of geomicrobiology, I organized a short course on biological/mineralogical interactions. I continue to do some research in bioleaching today.

The majority of my research is done in collaboration with others at UBC and at the California Institute of Technology, Oak Ridge National Laboratory, Cambridge University, and the Universities of Hamburg and Manitoba.