The spelling of "rare earth element" can be confusing due to the pronunciation of the word "earth." In IPA phonetic transcription, the word is pronounced /ɜːrθ/, with the "th" sound at the end being a voiced dental fricative. This can be mistaken for an "f" sound, leading some to spell it as "rare earths element." However, the correct spelling includes "earth" without an "s" at the end. Rare earth elements are a group of elements with unique properties used in electronics and other industries.
A rare earth element refers to any of the 17 chemically similar elements found in the Earth's crust, belonging to the group of elements known as the lanthanides. These elements include lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), and the related elements scandium (Sc) and yttrium (Y).
The term "rare earth" can be misleading, as it does not indicate the abundance of these elements in the Earth's crust. Although individually they are not particularly rare, their dispersion and extraction in concentrated forms make them economically valuable. Rare earth elements possess unique magnetic, optical, and catalytic properties, making them important in a wide range of applications, such as electronics, defense technologies, renewable energy systems, and high-tech industries.
Due to their critical importance in various sectors, rare earth elements have drawn significant attention from industries and governments. China is the largest producer and exporter of rare earth elements, accounting for more than 80% of global supply. This dominance has raised concerns among other nations about China's strategic control over the supply chain. Efforts are being made to develop alternative sources and improve recycling techniques to reduce dependence on a single country for these valuable elements.
In summary, a rare earth element is any of the 17 chemically similar elements found in the Earth's crust, with unique properties that make them indispensable in multiple high-tech sectors.