gems, opal, South Australia, Andamooka, Coober Pedy, Mintabie

South Australia's famous desert opalfields supply about 80% of the world output of precious opal, with current production coming almost entirely from the major fields at Andamooka, Coober Pedy and Mintabie, each of which is expected to increase output in the long term. This informative handbook, written by SA State Government experts on the subject, is a compilation of several existing reports that describe the geology and opal occurrences at numerous fields. The known extent of typical host rocks to the main opal occurrences suggests that there remains considerable potential for making numerous small finds across the northern part of the State.