I dont usually use gems in my own jewellery work, Ive been pursuing other kinds of preciousness and luminousity. Like gold and paint.
My uncle, Andrew, happens to be a gem trader and general mineral man- when I was a kid he sent me a box of awesome rocks, all kinds of sparkly and geometric stuff that he had prospected. ( Tip; excellent present for kids, paired with one of these)
Andrew also specialises in Tektites; which are weird glassy blobs that no one really knows much about , except they have definitely been in space. ( meteorites? volcanic spewage that went off-world and then came back down? etc, etc)
And what's possibly even more perplexing, is that no one really knows what to do with them either, but if you want one, Andrew Neale is your go-to. He's got boxes of them.
He can be found most saturdays at the St.Andrew's market or sundays at the Camberwell market. Or just ask me for whatever rocks you're after.