The recent discovery of gold deposits on the leaves of Australian Eucalyptus trees is more important for science and more common than you may think. Scientists have discovered small traces of gold in tree leaves before; they just never knew exactly where it came from.
The study that documented the findings of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) uncovered the mechanism by which plants turn leaves into gold: the tree's roots suck the mineral deep from the ground.
Researchers suspected this was the process but couldn't prove that the gold didn't come from surface deposits.
Through CSIRO's study, scientists have a much better understanding of how the whole operation works.
Eucalyptus roots suck gold (Au) as deep as 30 meters, according to the study. The roots function "as a hydraulic pump ... drawing up water containing the gold", CSIRO geochemist Dr. Mel Lintern told The Guardian.
The researchers learned why the gold is only found in the leaves and not the trunk or branches. Since it is probably toxic to plants, the mineral moves as far away from the life center of the organism and to the extremities, the study reported.
Though the leaf gold is only "one fifth the diameter of a human hair" and thus invisible to the human eye, the mineral deposit below it could potentially be larger and more profitable, according to The Guardian.
Resource companies could use gold trees as indicators for a more "cost effective and environmentally-friendly technique ," Lintern said.
According to Lintern, gold trees will only be a small aspect of gold exploration and that most companies will stick with their advanced technqiues. Still, they can use the trees to their advantage when necessary. The real benefits will be realized for other minerals Lintern said.
"By sampling and analysing vegetation for traces of minerals, we may get an idea of what's happening below the surface without the need to drill," he said. "It's a more targeted way of searching for minerals that reduces costs and impact on the environment.
"Eucalyptus trees are so common that this technique could be widely applied across Australia. It could also be used to find other metals such as zinc and copper," he said.
