Many U.S. states have proclaimed official state rocks, state minerals, state gemstones and state fossilseven state dinosaurs. I've started to look at other nations, and Australia has them too, including a national gemstone: opal. I've just made a new guide to those: "Geological Emblems of Australia."
I've also found that the Canadian provinces have their own official minerals and etcetera. What other nations should I check out?