Â鶹ֱ²¥ research has found tiny amounts of gold can be trapped inside pyrite, commonly known as \u2018fool\u2019s gold\u2019, which would make it much more valuable than its name suggests.<\/p>\n
This study, published in the journal Geology<\/em> in collaboration with the University of Western Australia and the China University of Geoscience, provides an in-depth analysis to better understand the mineralogical location of the trapped gold in pyrite, which may lead to more environmentally friendly gold extraction methods.<\/p>\n Lead researcher Dr Denis Fougerouse from Curtin\u2019s School of Earth and Planetary Sciences said this new type of \u201cinvisible\u201d gold has not previously been recognised and is only observable using a scientific instrument called an atom probe.<\/p>\n \u201cThe discovery rate of new gold deposits is in decline worldwide with the quality of ore degrading, parallel to the value of precious metal increasing,\u201d Dr Fougerouse said.<\/p>\n \u201cPreviously gold extractors have been able to find gold in pyrite either as nanoparticles or as a pyrite-gold alloy, but what we have discovered is that gold can also be hosted in nanoscale crystal defects, representing a new kind of \u201cinvisible\u201d gold.<\/p>\n \u201cThe more deformed the crystal is, the more gold there is locked up in defects. The gold is hosted in nanoscale defects called dislocations \u2013 one hundred thousand times smaller than the width of a human hair \u2013 so a special technique called atom probe tomography is needed to observe it.\u201d<\/p>\n Dr Fougerouse said the team also explored gold extraction methods and possible ways to obtain the trapped gold with less adverse impacts on the environment.<\/p>\n \u201cGenerally, gold is extracted using pressure oxidizing techniques (similar to cooking), but this process is energy hungry. We wanted to look into an eco-friendlier way of extraction,\u201d Dr Fougerouse said.<\/p>\n \u201cWe looked into an extraction process called selective leaching, using a fluid to selectively dissolve the gold from the pyrite. Not only do the dislocations trap the gold, but they also behave as fluid pathways that enable the gold to be \u201cleached\u201d without affecting the entire pyrite.\u201d<\/p>\n The study is supported by the Australian Research Council and the Science and Industry Endowment Fund. Dr Fougerouse is affiliated with The Institute for Geoscience Research (TIGeR), Curtin\u2019s flagship Earth Sciences research institute.<\/p>\n