There are many handholds and safety ropes, but you aren't allowed to carry anything with you because people have dropped their cameras and hats into the roadway below. I'm sure you can imagine some great disaster comedy there. Australia is a big supplier of neat, shiny rocks. Some of the best are opals. There is an area called Lightning Ridge, which is just about the only place where black opals come from.
Black opals have the best color and flash, and are generally the most prized.
I visited the national opal collection here, where they showed me some opalized dinosaur fossils. His fossilized remains have become opalized by the mineral content of the soil he died in and around. Of course, it could just have been something he ate. And most of us will be content just not paying tax anymore when it's our turn. This is a yowah nut which has become opalized.