A team of unlikely prospectors recently ventured into the arid land of the Goldfields-Esperance region in Western Australia, hoping to learn more about what was underneath its soil. The area earned its name for being rich in gold deposits—that were, however, notoriously difficult to find. So the researchers looked in an unlikely place: The trees.
Eucalyptus trees in this region are known for their resiliency, and for roots that reach impossibly deep to find the groundwater needed to keep themselves alive. It just so turns out that the elusive gold deposits are down there, too.
Chasing a longstanding rumor that the trees' leaves get their gold luster from the deposits, the scientists analyzed the leaves of eucalyptus trees in the area—and sure enough, they found traces of gold. Apparently, the trees' roots grew ten stories deep into the soil and absorbed gold particles from nearby deposits. To confirm that these particles came from the soil under the roots, they grew eucalyptus trees in gold-laced potting soil in a greenhouse. And sure enough—they found gold in those leaves, too.
The idea that plants absorb minerals from the soil around them is hardly new, but this is an extraordinary case. "Gold is probably toxic to plants and is moved to its extremities (such as leaves) or in preferential zones within cells in order to reduce deleterious biochemical reaction," reads a study about the research published today in Nature Communications. The authors also point out that this is "the first evidence of particulate gold within natural specimens of living biological tissue." That's a hell of a first, even for you alchemy nerds out there.
Don't go thinking you can get rich by cutting down eucalyptus trees, though. Each tree contains such a small amount of gold—46 parts per billion, to be exact—that it would take hundreds to compile enough for a wedding ring. But the trees could be used to scout the location of underground gold deposits. And since approximately 30 percent of the world's gold reserves are thought to lie underground in the Goldfields-Esperance region, the search may be well worth the trouble. More here.