Focus: Money May Not Grow On Trees, But Gold Leaf Does

By Fareesa Nahid / Sydney

Australian researchers have found minuscule nuggets of gold hidden inside the leaves of eucalyptus trees, in a discovery they say could help prospectors discover new deposits of the precious metal. 
    
Scientists from the Commonwealth Scientific and Industrial Research Organisation (CSIRO) made the find in the resource-rich Kalgoorlie region of Western Australia, which was the site of a major gold rush in the late 1800s. 
    
Geochemist Mel Lintern said it appeared the trees sucked up the gold particles from 100 feet below the ground through their roots. 
“The eucalypt acts as a hydraulic pump — its roots extend tens of metres into the ground and draw up water containing the gold,” he said. 
    
“As the gold is likely to be toxic to the plant, it’s moved to the leaves and branches where it can be released or shed to the ground.” 
    
In research published in the journal Nature Communications, the CSIRO said the leaf particles themselves would not trigger a new gold rush as they measure just a fifth the width of a human hair and are visible only through advanced X-ray imaging. Researchers involved in the study estimated it would take the gold from 500 eucalyptus trees to make a single wedding band. 
    
But they said the discovery presented a gilt-edged opportunity to improve the exploration methods used to search for gold, making them more efficient and environmentally friendly. 
    
“This link between... vegetation growth and buried gold deposits could prove instrumental in developing new technologies for mineral exploration,” they said. 
    
New discoveries of gold have fallen by 45% in the past decade, while prices have skyrocketed as reserves steadily dwindle — the cost of the yellow metal shot up by 482 percent between December 2000 and March this year. 
    
The CSIRO said scientists could use a technique known as “biogeochemical sampling” to give an indication of the presence of gold. 
    
“By sampling and analysing vegetation for traces of minerals, we may get an idea of what’s happening below the surface without the need to drill,” Lintern said.