CSIRO scientist discovers natural 'invisible' gold

June 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: Short wavelength plasmons observed in nanotubes

Related Stories

Short wavelength plasmons observed in nanotubes

July 28, 2015

The term "plasmons" might sound like something from the soon-to-be-released new Star Wars movie, but the effects of plasmons have been known about for centuries. Plasmons are collective oscillations of conduction electrons ...

Where is solar power headed?

July 22, 2015

Most experts agree that to have a shot at curbing the worst impacts of climate change, we need to extricate our society from fossil fuels and ramp up our use of renewable energy.

New methodology to study nanoparticle structures

July 13, 2015

Nanoscience is the study of materials that measure at the scale of one-billionth of a metre in length. While "tiny" is the very nature of this scientific field, nanoscience is a huge force behind modern day technology and ...

Recommended for you

Reshaping the solar spectrum to turn light to electricity

July 28, 2015

When it comes to installing solar cells, labor cost and the cost of the land to house them constitute the bulk of the expense. The solar cells—made often of silicon or cadmium telluride—rarely cost more than 20 percent ...

Meet the high-performance single-molecule diode

July 29, 2015

A team of researchers from Berkeley Lab and Columbia University has passed a major milestone in molecular electronics with the creation of the world's highest-performance single-molecule diode. Working at Berkeley Lab's Molecular ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.