Look around you, and you’ll see rare earth elements at work. A phone vibrates because a magnet moves a weight. Its screen was polished with cerium powder. Its connection to the rest of the world crosses oceans on cables amplified with erbium. If you drove today, a rare earth magnet helped you steer, and a cerium compound scrubbed the exhaust.
All of these devices function because of 17 metals collectively known as rare earth elements. The scientists who gave the group that name in 1794 created a misnomer. Cerium alone is about as common in the Earth’s crust as copper.
However, separating rare earth minerals from one another and from raw ore is intensely difficult. As a result, countries that control the processing of rare earth minerals have a lot of political leverage.
DW News 
The Guardian 
