Mount Edgar osarizawaite site, Mount Edgar Station, Marble Bar, East Pilbara Shire, Western Australia, Australiai

Regional Level Types
Mount Edgar osarizawaite site	Mountain
Mount Edgar Station	Mountain
Marble Bar	- not defined -
East Pilbara Shire	Shire
Western Australia	State
Australia	Country

James Henderson of Port Hedland presented a specimen of an unknown species to the CSIRO in June 1961. They determined it to be a new species, and the name 'edgarite' was assigned to it. In August 1961, the same species was discovered in Japan, and because the article about it was published first, Japan became its type locality. It was named osarizawaite after the mine, so the name edgarite was consigned to the dustbin.

From a historic perspective, the site in Western Australia is important, rendered useless as the article that was published about it, failed to describe its location. We are told its on Mount Edgar station, which narrows the search down to a few hundred square miles of remote, rocky arid hills. It is possible an exploration company later rediscovered the location, but whether it reported such a small site in its literature, or recognised it from the original article is unlikely.

The species was found as light green, friable aggregates of minute hexagonal crystals associated with barite, quartz, hematite, goethite and clay. It occurs in two narrow pipes resulting from cross folds in the oxidising portion of a steeply dipping narrow quartz-barite vein containing localised copper, lead and zinc minerals.

Described as located in a belt of quartz and sericite schist on the steeply dipping Warrawoona succession, on the south-east margin of a large craton, granite complex of Archaean age. It is assumed this is talking about the Pilbara Craton, with the Warrawoona Complex being a regional rock unit of the eastern Pilbara, so this does not narrow the search.

The vein also contains a complex mix of brochantite, linarite, limonite, manganese oxides, jarosite, clay, anglesite, traces of cerussite, and an unidentified hydrous zinc copper aluminium silicate, all associated with vuggy quartz and barite.

The West Australian Osarizawaite "shows a slight range of color between Ridgway's 'light Veronese Green' and 'Veronese Green'".

Other Regions, Features and Areas containing this locality

References