Rare-earth element
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),[a] 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,[b] 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.
Scandium and yttrium are considered rare-earth elements because they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties, but have different electrical and magnetic properties. All isotopes of promethium are radioactive, and it does not occur naturally in the earth's crust, except for a trace amount generated by spontaneous fission of uranium-238. They are often found in minerals with thorium, and less commonly uranium.
Because of their geochemical properties, rare-earth elements are typically dispersed and not often found concentrated in rare-earth minerals. Consequently, economically exploitable ore deposits are sparse. The first rare-earth mineral discovered (1787) was gadolinite, a black mineral composed of cerium, yttrium, iron, silicon, and other elements. This mineral was extracted from a mine in the village of Ytterby in Sweden. Four of the rare-earth elements bear names derived from this single location. Commercial production in modern times describes the reserves of the rare-earth elements in terms of "rare-earth oxides" (REOs) containing mixtures of various rare earth elements in oxide compounds.
The uses, applications, and demand for rare-earth elements have expanded over the years. In 2015, most REEs were being used for catalysts and magnets. The global move towards renewable energy technologies, such as electric vehicles (EVs) and wind turbines, along with advanced electronics, defence applications, and consumer electronics such as smartphones, has caused increased demand for REEs.
China dominates the rest of the world in terms of REE reserves and production; in 2019, it supplied around 90% of the global demand for the 17 rare-earth powders. The Chinese government has placed restrictions on its supply and sales of REEs since around 2010 for various reasons. After United States president Donald Trump escalated the trade war with China in 2025, China introduced further restrictions, leading other countries with known reserves to step up their exploration and production efforts. As of 2025, the US and Myanmar produce the second- and third-highest amounts of REEs, but Brazil and India have the second- and third-largest reserves of the metals.
Etymology
The term "rare" in "rare-earth" is a misnomer because they are not actually scarce, but rather because they are only found in compounds, not as pure metals, or perhaps because they were considered exotic at the time of their discovery. The "earth" part refers to an old term for minerals that dissolve in acids and thus are stable to oxidation.[12][13] They are never found in highly concentrated form, usually being mixed together with one another, or with radioactive elements such as uranium and thorium, and can only be separated from other materials or one another with difficulty. This makes them difficult to purify.[14]
Ukraine
Ukraine holds significant rare earth deposits, which have been at the center of the 2022 Russian invasion of Ukraine and peace negotiations.[149][150]
The largest rare-earth deposit in the United States is at Mountain Pass, California, sixty miles south of Las Vegas. Originally opened by Molycorp, the deposit has been mined, off and on, since 1951.[57][86]
A second large deposit of REEs at Elk Creek in southeast Nebraska[87] has been under consideration by NioCorp Development Ltd[88] who hopes to open a niobium, scandium, and titanium mine there.[89] That mine may be able to produce as much as 7,200 metric tons of ferro niobium and 95 metric tons of scandium trioxide annually.[90] As of 2022, financing is still in the works.[87]
As of 2006, the Bokan Mountain project in Alaska was being developed.[91] The Bokan-Dotson Ridge project, the location of a significant deposit of REE, was the subject of a Preliminary Economic Assessment released in January 2013,[92] and was reported by the Alaska Department of Natural Resources to be in an "advanced exploration phase" by Ucore Rare Metals in 2025.[93] However it has no operational capacity.[94]
In 2024 American Rare Earths Inc. disclosed that its reserves near Wheatland Wyoming totaled 2.34 billion metric tons, possibly the world's largest, and larger than a separate 1.2 million metric ton deposit in northeastern Wyoming.[95]
After China had announced new restrictions on access to their rare-earths in 2025,[81] the U.S. has been seeking alternative supply chains.[96] On 20 October 2025, President Trump signed a deal with the Prime Minister of Australia, Anthony Albanese,[97] over rare-earths and other critical minerals[81][98] that are needed for commercial sustainable energy production and technologically advanced military hardware. They each committed to provide at least US$1bn (A$1.54bn) towards a number of projects worth $US8.5bn (A$13bn) in both the US and Australian projects over six months.[97]
Greenland
In 2010, a large deposit of rare-earth minerals was discovered in Kvanefjeld in southern Greenland, which is an autonomous territory of Denmark.[109] Pre-feasibility drilling at this site has confirmed significant quantities of black lujavrite, which contains about 1% rare-earth oxides (REO).[110] The European Union has urged Greenland to restrict Chinese development of rare-earth projects there, but as of early 2013, the government of Greenland has said that it has no plans to impose such restrictions.[111] Many Danish politicians have expressed concerns that other nations, including China, could gain influence in thinly populated Greenland, given the number of foreign workers and investment that could come from Chinese companies in the near future because of the law passed December 2012.[112]