The term "Rare Earth" for the chemical elements of the lanthanide series is a historical misnomer. The elements in this series are not actually rare in abundance; instead, they are relatively abundant in the Earth's crust. The name "Rare Earth" originated from the 18th and 19th centuries when these elements were initially discovered and isolated.
Here are a few reasons why these elements came to be known as "Rare Earth" elements:
Early Discoveries: The first discoveries of these elements occurred in the late 18th century when they were identified in rare minerals such as cerite and gadolinite. At the time, these minerals were considered rare and difficult to find, leading to the belief that the elements themselves were scarce.
Similar Properties: The lanthanide elements share similar chemical properties and are challenging to separate from one another. They often occur together in the same mineral deposits, making it difficult to extract and isolate individual elements. This further contributed to the perception that they were rare.
Lack of Industrial Uses: Initially, the lanthanide elements had limited practical applications, and their significance in various industries was not fully recognized. This, combined with their challenging extraction and purification processes, contributed to their perceived rarity.
Over time, the understanding of the abundance and applications of the lanthanide elements has changed. They are now known to be relatively abundant in the Earth's crust, with some elements even being more abundant than common metals like lead or tin. These elements find applications in various technologies, including electronics, magnets, catalysts, and lighting.
Despite their misleading name, the term "Rare Earth" continues to be used to refer to the lanthanide elements due to their historical association and the established terminology in scientific literature.