Homeowner stumped after incredible backyard discovery: 'What an amazing find'
The Sydney woman said she had 'no idea' how the large chunk of quartz came to be in her garden.
Little thought is often given to what lies beneath the soil's surface, but buried deep underground is a history rich with minerals, including rare and profitable gold.
And while treasures are there to be found, a Sydney homeowner wasn't expecting to dig up a mammoth chunk of mineralised rock in her backyard so far away from Australia's historic mining towns, admitting to Yahoo News Australia she has "no idea how it got there".
The woman, who asked to remain anonymous, said she made the discovery "a few months ago" while working in her garden in Sydney's south.
"It was in a pile of dirt we were moving to clear way for a garden bed that was from the pool," the homeowner said. "We washed it and thought it was really cool".
The large metallic rock —which is gold in colour — has been identified as quartz — a common source for gold to form, along with ironstone. And while found in abundance across Australia, and the world, geologist and university professor John Kaldi said this particular one is "interesting" and "pretty".
That's because most quartz we see has "already been rounded off" for example sand grains at the beach, "That's all quartz," he told Yahoo. Additionally, the "metallic layers" shown in the photos indicate it could contain gold or silver.
Gold often found in quartz veins
The rock, which the woman said is about "the size of two fists", has been crystallised — evident by the pointy tips. "That means it's actually grown in a vein, and that's the nice thing about it," Kaldi, from Adelaide University, explained
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In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Minerals come to the surface from hydrothermal deposits — hydrothermal meaning hot water.
"Hot water comes from deep in the subsurface in geological formations that are up to thousands of metres," he explained. "Most of our gold, silver, lead, zinc, etc deposits in the world are associated with Quartz veins."
Rock's origin remains unknown
Jochen J Brocks, Professor of Geobiology at ANU agreed "it certainly looks like a genuine piece of quartz, slightly stained yellow on the surface by iron".
"I am sure it is not a fake, it would cost more to produce such a good fake than the value of the stone itself," he told Yahoo.
Kaldi said "there's no way of knowing the history of this or where it came from," suggesting it might have transferred from its original origin rather than having formed beneath the woman's backyard.
"If there is some gold in there or some silver, it would form an interesting bit of a block collector's collection," he said. "But without knowing the exact location of where this bit came from, it probably wouldn't have any commercial value."
Despite this, the woman told Yahoo she would "keep it for sure" with community members agreeing it's "an amazing find".
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