Discovered : by J.J. Berzelius in 1817 Isolated in Stockholm, Sweden Origin : The name is derived from the Greek ‘selene’, meaning moon. Description : Selenium can exist in two forms, as a silvery metal or as a red powder, and is used in photoelectric cells, photocopiers, solar cells and semiconductors. It is essential for some species, including humans, and our bodies contain about 14 milligrammes (1/20,000th of an ounce). Image : Lunar surface.