Rare-earth mineral in the context of "Critical minerals"

The rare-earth elements (REE), also called rare-earth metals, or rare earths, are a set of 17 nearly indistinguishable lustrous silvery-white soft heavy metals. The 15 lanthanides (or lanthanoids), along with scandium and yttrium, are usually included as rare earths. Compounds containing rare-earths have diverse applications in electrical and electronic components, lasers, glass, magnetic materials, and industrial processes. Rare-earths are to be distinguished from critical minerals, which are materials of strategic or economic importance that are defined differently by different countries, and rare-earth minerals, which are minerals that contain one or more rare-earth elements as major metal constituents.

The term "rare-earth" is a misnomer, because they are not actually scarce, but because they are found only in compounds, not as pure metals, and are difficult to isolate and purify. They are relatively plentiful in the entire Earth's crust (cerium being the 25th-most-abundant element at 68 parts per million, more abundant than copper), but in practice they are spread thinly as trace impurities, so to obtain rare earths at usable purity requires processing enormous amounts of raw ore at great expense.

Baotou is the second-largest city by urban population in Inner Mongolia, China. Governed as a prefecture-level city, its built-up (or metro) area within its five urban districts is home to 2,261,089 people while the total population is 2,709,378 as of the 2020 census.

Baotou's southern border is delineated by the Yellow river. The city's namesake, literally translating to "place with deer", is Mongolian, bringing about the nickname of "Lucheng" (Chinese: 鹿城; pinyin: Lùchéng), meaning "City of Deer". Alternatively, Baotou is known as the "City of Steel in the Grasslands" (草原钢城; Cǎoyuán Gāngchéng), since steel was a major industry in the city which is built on the Mongolian grassland and contains a large grassland park. Today, Baotou mines and refines over half of the rare-earth minerals produced in the world. This has led to environmental contamination near the industrial sites.

A gold rush or gold fever is a discovery of gold—sometimes accompanied by other precious metals and rare-earth minerals—that brings an onrush of miners seeking their fortune. Major gold rushes took place in the 19th century in Australia, Greece, Venezuela, New Zealand, Brazil, Chile, South Africa, the United States, and Canada while smaller gold rushes took place elsewhere.

In the 19th century, the wealth that resulted was distributed widely because of reduced migration costs and low barriers to entry. While gold mining itself proved unprofitable for most diggers and mine owners, some people made large fortunes, and merchants and transportation facilities made large profits. The resulting increase in the world's gold supply stimulated global trade and investment. Historians have written extensively about the mass migration, trade, colonization, and environmental history associated with gold rushes.

Yttrium is a chemical element; it has symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element". Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals and is never found in nature as a free element. Y is the only stable isotope and the only isotope found in the Earth's crust.

The most important present-day use of yttrium is as a component of phosphors, especially those used in LEDs. Historically, it was once widely used in the red phosphors in television set cathode ray tube displays. Yttrium is also used in the production of electrodes, electrolytes, electronic filters, lasers, superconductors, various medical applications, and tracing various materials to enhance their properties.