CSIRO scientist discovers natural 'invisible' gold

Jun 23, 2008

The search for these natural but 'invisible' nanoparticles is important. If they can be proved to exist, the knowledge will help give us a deeper understanding of how gold can be transported and deposited by geological processes, and therefore help explorers to find new gold deposits in Australia.

Now, hard evidence that gold nanoparticles have finally been seen in nature is presented in a paper published in GEOLOGY and authored by CSIRO Scientists from the Minerals Down Under National Research Flagship and CRC LEME, in collaboration with scientists from Curtin University and the University of Western Australia.

Lead author, CSIRO's Dr Rob Hough, explains that the particles were discovered in Western Australia. "In the southern areas of the State, groundwater is very salty and acidic. This water dissolves primary gold and re-deposits it as pure gold crystals on fracture surfaces and in open pore spaces," he says.

"On investigation of these crystals, there appeared to be a dark band across them. However, high magnification imaging showed the band was in fact, a mass of gold nanoparticles and nanoplates. These are identical to those being manufactured in laboratories around the world for their unique properties."

Clays from the fracture surface were then analysed. There was no gold visible, but analysis showed the clays contained up to 59 parts-per-million of gold. The research team concluded that the nanoparticles of gold they had imaged represented the 'invisible' gold in the clay, and that this nanosized gold was common in similar environments.

"The gold nanoparticles have not been identified earlier because they are transparent to electron beams and effectively invisible," Dr Hough says. "However, they are probably a common form of gold in this type of natural environment worldwide, where saline water interacts with gold deposits. They also provide the first direct observation of the nanoscale mobility of gold during weathering."

With gold fetching around (AU) $950 an ounce and expected to rise, this research is good news for Australia's gold explorers.

Source: CSIRO Australia

Explore further: Pressure probing potential photoelectronic manufacturing compound

add to favorites email to friend print save as pdf

Related Stories

Building 'invisible' materials with light

54 minutes ago

A new method of building materials using light, developed by researchers at the University of Cambridge, could one day enable technologies that are often considered the realm of science fiction, such as invisibility ...

Scientists discover gold's hidden value

Jun 20, 2014

(Phys.org) —Scientists from Cardiff are discovering new and unexpected uses for gold – a noble metal traditionally regarded as being chemically uninteresting due to its poor ability to react with other ...

Recommended for you

A new way to make microstructured surfaces

Jul 30, 2014

A team of researchers has created a new way of manufacturing microstructured surfaces that have novel three-dimensional textures. These surfaces, made by self-assembly of carbon nanotubes, could exhibit a ...

Tough foam from tiny sheets

Jul 29, 2014

Tough, ultralight foam of atom-thick sheets can be made to any size and shape through a chemical process invented at Rice University.

User comments : 0