Discovered : by J.A. Snaidecki in Vilno, Poland in 1808, and then rediscovered by G.W. Osann in Tartu, Russia in 1828 Origin : The name is derived from 'Ruthenia', the Latin name for Russia. Description : Like rhodium, one of the rarest metals on Earth. It is used to harden platinum and palladium and as a catalyst in the chemicals industry. Like gold, this metal can be found in the free state. Image : Soviet Civil Ensign circa 1921.