There's gold in them thar trees?
This is Sandra Tsing Loh with the Loh Down on Science, saying:
You've heard of gold leaf, but gold that's literally in leaves? It's true. Scientists know that gold particles in soil can be taken up by plants growing in that soil. And the highest concentration is in the leaves.
The question is, can particles of gold in leaves be used to detect bigger gold deposits below ground? Mineral explorers and prospectors hope so. As do geochemists from Australia's national science agency.
Working backwards, the Australian team journeyed to a known gold deposit. There they collected and analyzed leaves, twigs, and bark from—what else—eucalyptus trees. Not only ones that were growing right there, but also ones growing farther away.
Result? Trees growing over the deposit had 20 times more gold than the others! Up to 80 parts per billion. The average plant has only one to 2 parts per billion. The gold was from a layer of soil pretty deep underground.
This might mean professional prospectors could sample vegetation to assess gold content before starting costly mining projects.
My suggestion? Just look for smiling koalas with gold teeth.
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The Loh Down on Science is produced by LDOS Media Lab, in partnership with the University of California, Irvine, and 89.3 KPCC. And made possible by the generous support of the Gordon and Betty Moore Foundation.