Hi Islandstone, welcome to Prospecting Australia.
I have a lovely little agate somewhere that I found as a kid at Kitty Miller Bay on Phillip Island. Not too sure if you're still allowed to hunt for them there now though. The ocean had polished it perfectly round to an oval shape, and it's a beautiful red with from memory some dark and light rings around it too. I haven't seen it in years and suspect it's stored away at my parents place with all my other stuff from my childhood, including my bottle of gold panning finds (although, knowing my mother she may just as well have thrown out "the old bottle, and stones" that she found in with all my stuff :awful:
There are plenty of people on here though who are into Gems, Gold, Coins, Relics, and all kinds of stuff who I am sure would be able to help you with info.
Have you ever thought of detecting around where George Bass rowed his boat up the river/creek down there? You may be the first to find something that he or one of his party dropped while camping along the coast and exploring the rivers and creeks. You never know!
D.S