Historical information

Coorongite is a dark, rubber-like, highly resilient structureless algal deposit. In the Coorong district of South Australia it occurs in moderate quantities associated with the coastal swamps and sand dunes which extend for a considerable distance east of the mouth of the Murray. This particular specimen was recovered from the south of the Coorong River, South Australia. A type of sediment rich in organic matter, Coorongite is the unlithified end-member of the sapropelic coal series. The members of the sapropelic coal series can be ranked in order as sapropel (the unlithified form), sapropelic-lignite, and sapropelic-coal (the lithified forms) based on increasing carbon content and decreasing volatile content. Sapropel (Coorongite) is an unlithified dark, pulpy, fine organic mud containing concentrations of algae and miospores that are more or less identifiable.

Coorongite is typically found as an algae like substance, that can be found in irregular size pieces. Coorongite was believed to be dried up oil due to its rubber-like texture. The Coorongite is also soft to the point where it can be cut into with a knife or it can be broken and torn by hand.

Otherwise known as 'Kurangk', the Coorong River is home to the Ngarrindjeri people, which acts as both a place for gathering food and a spiritual place. In 1852 the first sight of Coorongite was found along the Coorong River. The finders mistook the Coorongite for dried up oil, which lead to the belief that there were oil reserves under the Coorong River. Between the 1860s and the 1930s the Coorong River became a place where mining oil and Coorongite became precedent.

Nowadays, the local council and the South Australian Government are working together with the Ngarrindjeri people to sustain and preserve the Coorong River and the culture that is with it.

Soon after gold was discovered in 1851, Victoria’s Governor La Trobe wrote to the Colonial Office in London, urging ‘the propriety of selecting and appointing as Mineral Surveyor for this Colony a gentleman possessed of the requisite qualifications and acquaintance with geological science and phenomena’. Alfred Selwyn was appointed geological surveyor in Australia in 1852 which began the Geological Survey of Victoria. Selwyn went on to collect geological samples and catalogue thousands of specimens around Australia. In 1853-69 the Geological Survey issued under Selwyn's direction sixty-one geological maps and numerous reports; they were of such high standard that a writer in the Quarterly Journal of the Geological Society of London bracketed the survey with that of the United States of America as the best in the world. During his years spent in Australia, Selwyn collected numerous significant geological specimens, examples of which are held in collections such as the Burke Museum.


Coorongite is considered to be a mineral with a unique texture, where it can be both hard and soft. Coorongite can also be considered to be a rare mineral, as it is only located along the Coorong River and due to the mining of it, has left very few sources. It was believed at one point that Coorongite could be used to replace oil.

This specimen is part of a larger collection of geological and mineral specimens collected from around Australia (and some parts of the world) and donated to the Burke Museum between 1868-1880. A large percentage of these specimens were collected in Victoria as part of the Geological Survey of Victoria that begun in 1852 (in response to the Gold Rush) to study and map the geology of Victoria. Collecting geological specimens was an important part of mapping and understanding the scientific makeup of the earth. Many of these specimens were sent to research and collecting organisations across Australia, including the Burke Museum, to educate and encourage further study.

Physical description

Three solid varyingly hand-sized pieces of wooden appearing organic matter derived from the river in the Coorong District in South Australia. A rubber-like, highly resilient structureless algal deposit.

Inscriptions & markings

Specimen 245 page 69 / in
Descriptive Register / "Elcestic
Bitumen, / Coorangite" South of /
Coorung River, South Australia . /
C. WIllman / 15/4/21