´óÏó´«Ã½

Archaeologists have said that a natural pearl unearthed in a remote part of Western Australia is more than 2,000 years old.

The pearl is described as "irreplaceable" by one of the senior researchers on the project, as it's the only one ever recovered from an ancient site in Australia. Unearthed during a 2011 dig in the Kimberley region, archaeologists from the University of Wollongong took four years to analyse and date the pearl using non-invasive technology to avoid damaging it, Associate Professor Kat Szabo . Carbon dating used on the surrounding shell established that it's around 2,000 years old.

But as the pearl was so round, and discovered near the heartland of Australia's cultured pearl industry, archaeologists had to prove it wasn't a modern creation which had simply sunk down into the ground. Round natural pearls are extremely rare in nature. "It didn't have the seed that cultured pearls have," Dr Szabo explains, adding that it had "all the classic signatures of a natural pearl".

While the pearl has a rose-gold tint, it's not clear whether that's the original colour, or a product of being buried underground for so long. But Dr Szabo says it's in great condition considering its advanced age. It will go on display at the Western Australian Maritime Museum later this month.

Next story: Female prison guards form dance troupe

Use #NewsfromElsewhere to stay up-to-date with our reports via .