Washington, July 18 : Scientists have found naturally occurring triangular and hexagonal plates of gold less than 20 nanometers thin, which is identical to those manufactured by humans, in salty groundwaters of Western Australia.
Nano gold is being developed for use in for drug delivery, optics, superconductors and catalysts, but until now, it was thought to be entirely manmade.
Now, according to a report in Discovery News, the Aussie nano gold in the water that gets as thin as six nanometers, is completely natural and previously escaped detection by electron microscopes.
"It's very, very similar to the colloidal gold people have been growing in laboratories," said Robert Hough of the Mining and Exploration branch of Australian government's research agency, CSIRO.
The gold nano particles had appeared as ghostly grey shapes in scanning electron microscope (SEM) images. By applying what's called "high-resolution secondary electron imaging in a field emission SEM," Hough and his team were able to look directly at the ultra thin gold particles.
At the moment, labs make their own nano gold by dissolving larger pieces of gold and growing the nano crystals.
But they have suffered from some of the same difficulties as the geologists looking for natural nano gold: being sure they know just what sort of nano gold particle they are dealing with.
According to Pablo Jadzinsky, who uses nanogold in organic chemistry research at Stanford University, whether natural nano gold will be of any use to labs is unclear because it depends on how hard it would be to purify the salty ground waters and isolate just the sort of nano gold that is desired.
But, geologists aren't worried about laboratory applications, however. Instead, they are looking at how the nano gold could lead to large, extractable deposits of the precious metal.
"It has big implications for exploration," said Hough. "It's really a fundamental of how gold moves around," he added.
"And now that they know how to look for the nano gold, there is a way to look for signs of gold deposits anywhere there is salty groundwater," according to Hough.