I know theres areas all around mt. isa/cloncurry if you do some google searching and on here and you can find the exact areas that have chevron amethyst (Quamby, QLD, 50km from cloncurry), agate and lots of other crystals
Theres a youtube channel "liz kreate" that has videos on minerals in QLD:
youtube.com/watch?v=T8grAUmB124
Try to get a copy of this book , The Australian Gemhunters Guide by K.J . Buchester . List a lot of places around Australia . Maybe you can pick a copy up on E-bay .