Athletes aren’t the only ones going for gold

By Sarah Frazer

6 April 2018

Salmon gums illuminated by the golden- red light of sunset.

Salmon Gums at sunset in the Western Australian wheatbelt near Bruce Rock, WA.

We’re working on new techniques to detect hidden gold deposits.

The Gold Coast is soon to be filled with hopeful athletes, vying to take home a Commonwealth Games gold medal in a range of sports from athletics to wrestling. But Australia isn’t just the host for this year’s Games, the 21st since their inception in 1930. It’s also the world’s second largest producer of gold annually. Gold is currently worth over AU$45,500 per kilogram, so it’s no wonder why gold mining has remained popular long after the gold rush days of old reached an end.

People have been mining gold in Australia for over 150 years. As a result, many of the obvious and easily accessible gold deposits are being depleted. Just like technology is helping athletes break records at the outer-limits of human ability, it’s changing the way we find gold.

Long gone are the days of searching for marble outcrops in the hopes that there would be valuable nuggets underneath. We’re developing a new, environmentally friendly way to find gold by looking at a source you wouldn’t expect: gum leaves.

Talk about green and gold

When you hear the phrase “gold leaves” you’d be tempted to think of surreal trees of glistening precious metal. The gold bearing gum leaves that our scientists have been inspecting in the Kalgoorlie region of Western Australia are anything but. In fact, on close inspection, there’s no obvious sign that they’re anything other regular gum leaves. Despite their somewhat ordinary appearance, they’re paving the way for gold detection on an atomic scale.

How does it work?

Eucalypts trees have roots that extend tens of metres into the ground, pumping precious water and minerals to the leaves. Gold may be valuable to us, but it can be harmful to the plants, and can have toxic effects if allowed to build up. To save itself from the potentially lethal gold, the trees move the gold particles to their leaves, where it can be released as the leaves shed to the ground.

We use advanced x-ray imaging to examine the leaves of these trees to create images highlighting the traces of gold and other minerals nestled within their structure.

Don’t leaf your day job yet

Before you go collecting armfuls of leaf litter in the hopes of striking it rich, you need to know the trace nuggets found in leaves are about one fifth the size of a human hair.

That doesn’t mean we’re find gold in leaves for nothing. The leaves provide a golden opportunity of further mineral exploration, with the potential to reveal gold ore deposits buried as deeps as the roots of the eucalypts go. This means we have a technique for detecting precious metal without the need for a drill.

Talk about a gold-winning idea!

Want more golden ideas?

We use x-ray vision on more than just leaves