Summary: The seventeen elements that make up rare earths began to be discovered at the end of the 18th century, but it was not until after the Second World War that progress was made in their applications. Today we have rare earths in euro banknotes to prevent counterfeiting and in mobile phones so that they can be tactile and emit sound and light. In our technology-driven culture, the list of items that contain them is very extensive. They are indispensable for green technologies, hybrid cars and wind turbines; they make it possible to produce more powerful, lighter magnets that allow ever-smaller household appliances; they are needed to manufacture night-vision goggles, cruise missiles and other weapons… How has our knowledge of rare earths advanced to reach today’s great dependence? This book addresses the path followed from the pure scientific discovery of some rare earths in the mine of the Swedish village of Ytterby to the present day, when they have become costly metals that are technologically critical for our society