Australia’s oldest natural pearl found in an excavation uncovered by UNE researchers

Published 10 June 2015

A 2,000-year-old natural marine pearl has been discovered by researchers at the University of New England (UNE) and the University of Wollongong (UoW) after archaeological excavations on the remote north west Kimberley coast of Western Australia.

Isabelle Balzer and pearl . Photo credit Yinika Perston.

Isabelle Balzer – a rare find . Photo credit Yinika Perston.

The pearl is the oldest recovered from an excavation in Australia and is about 5mm in diameter. Round natural pearls are also extremely rare in nature.

The University of New England’s Adjunct Professor, Dr June Ross with the late Professor Mike Morwood (UoW) and Dr Kira Westaway from Macquarie University led the ARC Linkage project, Change and Continuity in partnership with members of the Wunambal Gaambera Aboriginal Corporation, while UNE’s Dr Mark Moore directed the excavations and Professor Iain Young authored the paper.

“We were about 4 days into the excavation in the Brremangurey Rockshelter, a site adjacent to the shoreline of Admiralty Gulf. A team was sieving the excavated deposits made up of a dense layer of shell and charcoal. It was tedious and filthy work, before one of our PhD students, Isabelle Balzar suddenly let out a cry and, much to everyone’s surprise, drew out a pearl in her filthy hands. It was totally unexpected – the sort of find that makes excavating so exciting,” Dr Ross said.

Traditional Owners from Kandiwal and Kalumburu working on the project were amazed at the find and were keen to have it analysed.

Dr Ross said the pearl’s value lies in its scientific significance.

“We know from the excavation that shellfish formed a significant part of the Aboriginal diet in this area of the Kimberley over the past 2000 years or so. Oyster shell found amongst other shellfish indicate that oysters were sought after – both for their meat and for the shell itself. We know that pearl shell was traded great distances from the Kimberley and used for ritual purposes in places as far away as the Western Desert,” said Dr Ross.

The age of the pearl was established by radiocarbon dating of the surrounding deposit.

Additional testing by UNE using micro-computed tomography confirmed that it an ancient natural pearl and enabled researchers to establish that it had grown inside an oyster for over a decade before the animal was harvested, probably for eating.

Additional analysis was undertaken by Associate Professor Kat Szarbó (UoW) and UoW PhD candidate Brent Koppel. Their paper jointly authored by Dr Mark Moore and Dr Matt Tighe is published in the Australian Archaeology Journal (June 2015) volume 80,pp. 112-115 and is available on Open Access.

The Brremangurey Pearl will be on display as part of the Lustre Exhibition to be held at the Western Australian Maritime Museum opening on the 20th June, 2015.

The Change and Continuity project was funded by an Australian Research Council Linkage Grant (Industry Partners: Kandiwal Aboriginal Corporation, The Kimberley Foundation Australia, Department of Environment (WA) and Slingair and Heliwork) with the Wanumbul Aboriginal Corporation. Collaboration with Cygnet Bay Pearl Farm assisted with the analysis of the pearl.