2012 Southern Sky Crux Domed $5 Silver ProofCrux, also known as the Southern Cross, is the smallest but most famous constellation in the southern sky. It is easily recognisable due to its bright stars, including Acrux and Mimosa. Crux has great navigational and cultural significance, especially for Southern Hemisphere explorers and indigenous peoples of Australia and South America. Note: outer box is quite sticky which was a very common issue for this series.