Editing Opal (section)

=== Australia ===
The town of [[Coober Pedy]] in [[South Australia]] is a major source of opal. The world's largest and most valuable gem opal "[[Olympic Australis]]" was found in August 1956 at the "Eight Mile" opal field in Coober Pedy. It weighs {{convert|17000|carat|kg lb}} and is {{convert|11|in|mm}} long, with a height of {{convert|4+3/4|in|mm|abbr=on}} and a width of {{convert|4+1/2|in|mm|abbr=on}}.<ref>{{cite book |last1=Cram |first1=Len |year=2006 |title=A history of South Australian opal, 1840–2005 |location=Lightning Ridge, NSW |publisher=Len Cram |isbn=978-0975721407 |oclc=225050989}}</ref>

The [[Mintabie, South Australia|Mintabie Opal Field]] in South Australia located about {{convert|250|km|abbr=on}} northwest of Coober Pedy has also produced large quantities of crystal opal and the rarer black opal. Over the years, it has been sold overseas incorrectly as Coober Pedy opal. The black opal is said to be some of the best examples found in Australia.

[[Andamooka, South Australia|Andamooka]] in South Australia is also a major producer of matrix opal, crystal opal, and black opal. Another Australian town, [[Lightning Ridge, New South Wales|Lightning Ridge]] in [[New South Wales]], is the main source of black opal, opal containing a predominantly dark background (dark gray to blue-black displaying the play of color), collected from the [[Griman Creek Formation]].<ref>{{cite news |title=The black-opal hunters of outback Australia |last1=Osborne |first1=Zoe |last2=Kitanov |first2=Alex |url=https://www.aljazeera.com/features/longform/2022/7/17/australia-black-opal-miners |newspaper=Al Jazeera |date=17 July 2022 |access-date=8 August 2022}}</ref> Boulder opal consists of [[concretion]]s and fracture fillings in a dark siliceous [[ironstone]] matrix. It is found sporadically in western Queensland, from Kynuna in the north, to [[Yowah]] and [[Koroit opal field|Koroit]] in the south.<ref>{{cite web|url=http://www.nrw.qld.gov.au/mines/fossicking/opal.html|title=Queensland opal|archive-url=https://web.archive.org/web/20071013164838/http://www.nrw.qld.gov.au/mines/fossicking/opal.html |archive-date=13 October 2007 }}</ref> Its largest quantities are found around [[Jundah]] and [[Quilpie]] in [[South West Queensland]]. Australia also has opalized [[fossil]] remains, including dinosaur bones in New South Wales<ref>[https://www.abc.net.au/news/2018-12-05/weewarra-dinosaur/10583990 First dinosaur named in NSW in nearly a century after chance discovery] ''ABC News'', 5 December 2018. Retrieved 5 December 2018.</ref> and South Australia,<ref>[https://www.abc.net.au/news/2018-12-03/rare-dinosaur-fossil-found-in-sa-after-disappearing-for-45-years/10575208 Rare dinosaur fossil discovered on internet after disappearing for decades] ''ABC News'', 3 December 2018. Retrieved 3 December 2018.</ref> and marine creatures in South Australia.<ref name="samuseum.sa.gov.au">{{cite web|url=http://www.samuseum.sa.gov.au/explore/museum-galleries/opal-fossils|publisher=South Australian Museum|title=Opal Fossils|access-date=3 March 2014|url-status=live|archive-url=https://web.archive.org/web/20140213204022/http://www.samuseum.sa.gov.au/explore/museum-galleries/opal-fossils|archive-date=13 February 2014|df=dmy-all}}</ref>