Lightning Ridge has the greatest number and diversity of opalised fossils in Australia. It is one of the most productive and scientifically significant fossil sites in the country, and the only major site in NSW with dinosaurs.
Three Australian dinosaur species have been described from Lightning Ridge material, but there are many more dinosaur specimens in the AOC collection that have not yet been studied or named. Other fossils include: turtles, crocodiles, fish, birds, early mammals, mussels, snails, giant marine reptiles, pine cones, plant stems and seeds.
The Australian Opal Centre has 4000 or more fossils in its collection, worth an estimated $3 million, but with Jenni and Elizabeth the only palaeontologists on site, much of it has yet to be studied.