There are between 15 and 17 of them (depending how you classify them), including such exotic sounding substances as holmium, praseodymium, cerium, lutetium, ytterbium, gadolinium or - my own personal favourite - promethium.
They may be obscure but they have been transforming all sorts of industries. Wind turbine manufacture is a good example.
Henrik Stiesdal is celebrated as one of the fathers of the modern wind industry. He built his first turbine on his family's farm in Denmark as a teenager, and has been perfecting his designs ever since.