Gemstones, Minerals & Rocks of Wyoming: A guide for Prospectors and Rock Hounds. Wyoming was once known as the Jade State, but from 1977 to 2007, one geologist (Professor Hausel, also known as the GemHunter) changed this designation by finding more than a hundred gemstone, gold, diamond and mineral occurrences in the Cowboy State such that the state is now better known as the Gemstone state.