<P> Until 1948, most of the world's rare earths were sourced from placer sand deposits in India and Brazil . Through the 1950s, South Africa took the status as the world's rare - earth source, after large veins of rare earth bearing monazite were discovered there . Through the 1960s until the 1980s, the Mountain Pass rare earth mine in California was the leading producer . Today, the Indian and South African deposits still produce some rare - earth concentrates, but they are dwarfed by the scale of Chinese production . In 2010, China produced over 95% of the world's rare - earth supply, mostly in Inner Mongolia, although it had only 37% of proven reserves; the latter number has been reported to be only 23% in 2012 . All of the world's heavy rare earths (such as dysprosium) come from Chinese rare - earth sources such as the polymetallic Bayan Obo deposit . In 2010, the United States Geological Survey (USGS) released a study that found that the United States had 13 million metric tons of rare - earth elements . </P> <P> New demand has recently strained supply, and there is growing concern that the world may soon face a shortage of the rare earths . In several years from 2009 worldwide demand for rare - earth elements is expected to exceed supply by 40,000 tonnes annually unless major new sources are developed . </P> <P> These concerns have intensified due to the actions of China, the predominant supplier . Specifically, China has announced regulations on exports and a crackdown on smuggling . On September 1, 2009, China announced plans to reduce its export quota to 35,000 tons per year in 2010--2015 to conserve scarce resources and protect the environment . On October 19, 2010, China Daily, citing an unnamed Ministry of Commerce official, reported that China will "further reduce quotas for rare (-) earth exports by 30 percent at most next year to protect the precious metals from over-exploitation". The government in Beijing further increased its control by forcing smaller, independent miners to merge into state - owned corporations or face closure . At the end of 2010, China announced that the first round of export quotas in 2011 for rare earths would be 14,446 tons, which was a 35% decrease from the previous first round of quotas in 2010 . China announced further export quotas on 14 July 2011 for the second half of the year with total allocation at 30,184 tons with total production capped at 93,800 tonnes . In September 2011, China announced the halt in production of three of its eight major rare - earth mines, responsible for almost 40% of China's total rare - earth production . In March 2012, the US, EU, and Japan confronted China at WTO about these export and production restrictions . China responded with claims that the restrictions had environmental protection in mind . In August 2012, China announced a further 20% reduction in production . These restrictions have damaged industries in other countries and forced producers of rare - earth products to relocate their operations to China . The Chinese restrictions on supply failed in 2012, as prices dropped in response to the opening of other sources . The price of dysprosium oxide was 994 USD / kg in 2011, but dropped to 265 USD / kg by 2014 . </P> <P> On August 29, 2014, the WTO ruled that China had broken free - trade agreements, and the WTO said in the summary of key findings that </P>

Where are mines of rare earth elements found