Australia's Identified Mineral Resources 2010 presents estimates of Australia's mineral resources at end of December 2009 for all major and several minor mineral commodities (Table 1) based on published and unpublished data available to Geoscience Australia. These resource estimates provide a long term view of what is likely to be mined. They are compared with national totals of ore reserves for each commodity, which provides the industry view of what is likely to be mined in the short to medium term. Mine production data are based on figures from the Australian Bureau of Agricultural and Resource Economics and Sciences. World ranking of Australia's mineral resources have been calculated mainly from information in publications of the United States Geological Survey. A summary of significant industry developments also is presented. Australia's Identified Mineral Resources 2010 provides information on and analysis of mineral exploration expenditures in Australia for 2008-09 and the calendar year 2009. Trends in expenditure are presented and discussed.