Mineral Monday: Bornite
The iridescent purple-blue bornite crystal is not only a critical resource for South Australia, but is also an important addition to any mineral collectors’ repertoire.
LAST WEEK IT WAS reported that South Australia had made bornite an emblem of the state with the hope that this would promote the SA mineral resources industry.
Commonly referred to as ‘peacock ore’ because of its iridescent purple-blue hues, bornite is mined and smelted to produce copper metal, which is then used to make electrical wires, coins and plumbing pipes.
However, the crystal has also proved to be an important addition to any serious mineral collectors’ repertoire.
Ben McHenry, the SA Museum’s senior collection manager of earth sciences, told Australian Geographic that collectors aim to have representative samples from various localities, and that various mineral specimens are prized for their rarity and aesthetics.
The museum recently acquired the world’s finest specimen of bornite, which was extracted from the Olympic Dam mine in 2003. “Individual crystals of the species are very rare as it usually occurs as masses within ore bodies,’ Ben said. “This unique specimen comprises the largest known single crystal of the species in the world.
“Currently the international bornite market is dominated by small but exquisite crystals coming from Kazakhstan Good crystals also come from the Congo [formerly Zaire] and Zimbabwe.
“The county of Cornwall in England has produced many bornite specimens. The Olympic Dam specimen is exceptional for its size, being two or three times that of what is commonly found.”
Although bornite can be found in locations across the world, this colourful ore plays a unique role in the history of SA’s early mining industry. Ben explained that bornite was vital to the early development and prosperity of the State.
“Many people don’t realise that South Australia had the first metal mines in the country…but it was the discovery of the copper deposits at Kapunda in 1842 and Burra in 1845 that marked the start of Australia’s first mining boom, and gave the state its nickname — ‘The Copper Kingdom’,” he said.
Discovery of new deposits of bornite have continued with SA currently operating four major poly-metallic copper mines in Olympic Dam, Prominent Hill, Kanmantoo and Hillside. Ben added that the State’s economy would suffer without the ore’s contribution to building, plumbing and heating, automotive, power, air conditioning, refrigeration and telecommunications.
Ben explained that the SA Museum’s mineralogy section has for decades been the premier mineral research group in the country and that bornite has figured highly in the museum’s research into sulphide mineralogy.
You can find the details of the exhibition, ‘Copper: A richly South Australian resource’ here.