Production commenced at Oraparinna, 500 km north of Adelaide, in 1940. Normandy Industrial Minerals, which operated the deposit from 1984, transferred the mine to Unimin Australia Ltd in 2000, continuing the mine's long history as Australia's largest supplier of industrial-grade barite. The mine, comprising seven underground levels, works a system of 1-2 m wide veins which have developed in tensional fractures within Adelaidean Wilpena Group sediments in a graben structure extending from the northeastern corner of the Oraparinna Diapir. Ore is trucked 160 km to a treatment plant at Quorn where three industrial grades of barite - A, Standard and B - depending on colour, are produced for use in surface coatings, plastics fillers and mould coatings at Olympic Dam. Some A and Standard grade material is trucked to Gillman in suburban Adelaide for fine milling. 2002 production of 5248 tonnes is the largest since 1996.
From: [url]http://www.pir.sa.gov.au/minerals/geological_survey_of_sa/commodities/barite[/url]