What is another word for rare-earth metals?
Pronunciation: [ɹˈe͡əɹˈɜːθ mˈɛtə͡lz] (IPA) 
Rare-earth elements are a group of 17 chemical elements, including yttrium and the lanthanides. Lanthanides includes elements like cerium, europium, gadolinium, lanthanum, neodymium, praseodymium, promethium, samarium, etc. which have unique electronic, magnetic, and optical properties. These elements are commonly referred to as rare-earth metals. They are vital to modern technology, as they are used in electronics, magnets, and renewable energy technologies such as wind turbines. Synonyms for rare-earth metals include rare-earth elements, rare-earth minerals, and lanthanides. These elements are rare because they are not found in large concentrations in most parts of the world, and are difficult and expensive to extract.
