There’s evidence of Aboriginal occupancy in Australia for 20,000 years or more. Given the strength of the Australian Gold Rush, and the abundance of gold found literally lying on the ground in certain areas, it seems unusual to think that Aboriginal Australians found no use for such an easily attainable metal; especially considering the exorbitant use in civilisations such as Ancient Egypt or Rome.
So to answer your question initially, Indigenous Australians did not utilize gold prior to European colonisation. The lack of use actually isn't that unusual when you consider that Indigenous Australian society was not the same as Ancient Egypt or Rome.
Indigenous Australian society was not one that contained settlements and permanent structures. This isn't to say that it was completely nomadic/hunter-gatherer based, recent authors such as Gammage and Pascoe (though Pascoe does have his critics) contend that Indigenous Australians performed styles of farming that don't fit a 'Eurocentric' view of agriculture.
However, unlike Ancient Egypt or Rome, or even the Native Americans, Indigenous Australian society lacked the reason to utilize gold. For these 'civilisations' gold was utilized mostly for decoration, both for buildings and for people. Indigenous Australian society was more practical than this, in part due to the lack of permanent settlement, which meant there was no need to adorn buildings with gold, and little need to adorn people with a heavy and unnecessary element.
For decorating people, Indigenous Australians would regularly utilize ochre, which to them essentially worked as their gold. It was used in all types of rituals, seen by many Indigenous cultures as the blood of their ancestors (specifically this was red ochre), and used in trades for more practical items such as weapons and tools. Essentially, Indigenous Australians did not have reasons to use gold in the same manner as the civilisations you mention, and at the same time, Ochre basically worked as a gold substitute for Indigenous society. It should be noted that Indigenous Australians did mine for stone and flint, so this wasn't due to an inability to mine, but moreso the previous societal reasons mentioned.
Sources used:
- Flood, J., 1983, Archaeology of the Dreamtime, William Collins Pty Ltd, Sydney.
- Hiscock, P. and Mitchell, S., 1993, Stone Artefact Quarries and reduction Site in Australia: Towards a Type Profile, Australian Heritage Commission, Technical Publications Series No. 4, Australian Government Publishing Service, Canberra.
- Horton, D., 1994, The Encyclopaedia of Aboriginal Australia, Aboriginal and Torres Strait History, Society and Culture, Aboriginal Studies Press, Australian Institute of Aboriginal and Torres Strait Islander Studies, Canberra.