rare earths – The OM Blog by Heizer, Render, & Munson

OM in the News: Europe’s Move Towards Rare-Earths

Europe is trying to get itself on the global rare-earths map. Estonia, once a textiles hub for the Russian Empire, is now host to Europe’s biggest production plant for the kinds of rare-earth magnets needed in electric cars and wind turbines. It is part of Europe’s push to secure a foothold in a global supply chain dominated at every step by China, reports The Wall Street Journal (Nov. 16, 2025). Financed in part by the EU, the factory is expected to begin deliveries to companies in 2026.

Production of rare-earth magnets is expected to increase at the factory in Estonia, but it still isn’t expected to meet Europe’s projected demand.

The problem: Even at the new factory’s initial planned capacity of 2,000 tons of permanent magnet material, the plant will produce a fraction of what European manufacturers need. There are plans to scale up production to 5,000 tons, but that is still a long way from being enough to break Europe’s dependence on China. Total European demand is forecast to reach about 45,000 tons by 2030. (Companies in the U.S. are planning to build more than 40,000 tons of capacity by 2030).

After China imposed new export restrictions for rare earths this year, the U.S. stepped up subsidies and other measures to support the industry, spurring a race to build out American mining, processing and manufacturing capacity. Rare earths are also essential to manufacturing many defense systems. European auto suppliers were already eager to diversify their permanent magnet sources before China’s move.

Rare-earth magnets are widely used in products such as electric cars and wind turbines

Europe prospered over recent decades in a global trading system that allowed it to import cheap gas from Russia and rare earths from China, powering its industrial base. But Russia’s invasion of Ukraine and China’s move to restrict rare-earth exports showed how dependent the continent had become on those countries. Europe has some rare-earth processing and recycling facilities but no active rare-earth mining. For now, EU producers are relying on customers being willing to pay a premium to avoid dealing with China’s restrictions.

Classroom discussion questions:

Why does China exert such power over the rare earth supply chain and why is that supply chain so important?
What else can the U.S. and EU do?

OM in the News: The Magnet Supply Chain and Auto Production Problems

In the auto industry, rare-earths are what allow electric-vehicle motors to function at high speed. They are also used in less exotic, though no less critical, functions performed by such parts as windshield wipers and headlights.

Ford shut down Explorer production at its Chicago plant in May because of a rare-earth shortage

China was supposed to have eased export controls on rare-earth magnets as part of a 90-day tariff truce agreement with the White House, but the country has slow walked license approvals for magnets. As exports of rare-earth magnets have virtually ground to a halt, carmakers face hard decisions about whether they can continue to keep some plants operating. Several production lines and plants across Europe have already closed, with more impacts expected in the coming weeks as inventories deplete, reports The Wall Street Journal (June 5, 2025). U.S., Japanese, and Indian vehicle production are also reducing or shutting down without more Chinese rare-earth components.

Car companies are looking at alternative sources for magnets in Europe and Asia, instead of purchasing them directly from Chinese factories as they do currently. But none of these sources would provide enough magnets to support the demand from the industry. And China controls almost all of the refining capability that transforms raw minerals into usable forms.

The lack of magnets hits EVs and hybrid vehicles harder than conventional cars and trucks. A typical EV contains far more rare-earths than a gasoline-powered model, but rare-earth magnets are found throughout any modern vehicle.

One option to conserve dwindling magnet supplies is reverting to older electric-motor technology that doesn’t make use of rare-earth magnets. Carmakers stopped using those motors because the current versions are cheaper and more efficient. They are also considering stripping out some premium features, such as adjustable seats, that make use of several tiny electric motors. High-end speaker systems that use rare-earth magnets could also be replaced with downgraded versions.

Classroom discussion questions:

As Ford’s head of supply chains, what are your options?
What is the long-term solution?

OM in the News: EV Jitters Over a Rare Earth

Caught in the middle of the U.S.-China trade war is a paper clip-size magnet that is vital to every new electric vehicle on the road. The magnet is made with dysprosium– a rare-earth mineral. More than 90% of refined dysprosium comes from China, and it is used in magnets that power everything from medical equipment to EV motors. (The magnets are used in the spinning portion of the EV motor that turns the wheels).

In its retaliation against U.S. tariffs, China slowed exports of several rare-earth minerals and magnets this month, setting off a panic among U.S. automakers. Rare earths, by the way, are used in almost everything that turns on. So far no other country has been able to produce them at the same scale and cost as China.

“You cannot build the motor without the magnet. If we want electric-vehicle production to continue to happen in the U.S., this has to be solved,” said one auto exec. Nearly 900,000 EVs were built in the U.S. last year.

The minerals are abundant in nature but difficult to refine into their pure form. They are the essential building blocks of much of modern technology, forming parts of everything from satellites and jet fighters to CT scanners and iPhone speakers.

The potential chaos related to the slowing of one link in the automotive supply chain illustrates how dependent the modern car industry is on global trade, writes The Wall Street Journal (April 28, 2025). America’s disadvantage is twofold: There is currently only one large-scale dysprosium mine in the U.S., and processing facilities are only now coming online. The development of a new mine takes an average of 29 years in the U.S.

China’s head start on mining and extracting the precious elements makes it difficult to build alternative sources. A mine in China, to produce from an ore to oxide, costs $11 to $15 a kilogram. For a mine in Brazil, it’s $35 to $40 a kilogram, and even higher in the U.S. or Australia.

Classroom discussion questions:

Why are rare earths so important? Name several products that require them.
What are the alternatives that U.S. auto supply chain managers have?

OM in the News: Top Five Global Supply Chain Risks

The supply chain landscape continues to evolve at an unprecedented pace. A new report in Material Handling & Logistics (Jan. 15, 2025), identifies the top five most likely supply chain events that could impact companies in 2025.

Climate Change — 90% Risk Score Driven by shifting climate patterns and record-high temperatures, extreme weather events are a dominant risk to the supply chain. Volatile flooding has the potential for deep disruption. Indications point to the state of ocean temperatures being elevated in 2025 and beyond, with the potential for record-breaking highs.

Geopolitical Instability with Increased Tariff Risk – 80% Risk Score

The following major geopolitical events are likely to impact global trade in 2025:

• Ongoing Houthi attacks on cargo and container ships in the Red Sea continue to lead to longer transit times and equipment imbalance.

• Continued conflict in Ukraine could destabilize manufacturing and trade activities, putting European economies at further risk.

• Increased Chinese military drills near Taiwan could hinder trade through major sea routes, affecting global container shipping flows.

*The automotive, semiconductor, and manufacturing industries are possibly at risk due to proposed tariffs by the U.S.

Cybercrime – 75% Risk Score. Escalating cybersecurity risks in 2025, driven by the growing reliance on AI, IoT devices and interconnected systems include:

• Growing reliance on AI and cloud computing within supply chains is creating new “back door” opportunities for bad actors.

•Cyberattacks via sub-tier supply chains where criminals can more easily exploit common programming errors and vulnerabilities, allowing them into organizations via phishing and software connection links.

Rare Metals and Minerals– 65% Risk Score

• Within a politically charged atmosphere between the West and the major commodity producers – China and Russia – companies will face new tariffs and sanctions on critical metals.

• China could impose broader export restrictions, highlighting the need to diversify sourcing strategies. Lack of supplier diversity complicates procurement, leads to supply shortages and makes the price of affected commodities particularly vulnerable to trade tensions and eventual tariffs or sanctions.

Forced Labor – 60% Risk Score A growing crackdown on forced labor across industries will increase pressure on companies who are facing scrutiny to manage and eliminate suppliers violating human rights. Anticipated risks in 2025 include: Labor conditions in China, a cascade of legislation to address lax forced labor issues, the global concentration of commodities (like palm oil and vanilla) that originate in countries cited for modern slavery.

Classroom discussion questions:

What can an OM team at a manufacturer do to mitigate these risks?
Do you agree with these rankings? Would you add other risk factors?

OM in the News: The Rare-Earth Supply Chain Issue

The U.S. and Europe would love to cut their dependence on China for rare earths, reports The Wall Street Journal (July 16, 2024). Standing in the way of that ambition are low prices and Beijing’s willingness to throw its weight around to keep the market down.

Rare earths are a set of 17 metallic elements that are an essential part of many high-tech devices.

Rare-earth prices have plummeted this year and are now hovering at 3-year lows. The price of neodymium, a silver-gray alloy, has fallen by almost 20% this year to $50,000 a metric ton. Other rare earths are down even more.

Today, these neodymium minerals are mainly used in permanent magnets for a range of essential household items such as TVs, refrigerators and headphones. Increasingly, though, the magnets also help turn motors in electric vehicles, wind turbines and robots. By 2030, such high-tech products are expected to account for 2/3 of demand for neodymium permanent magnets.

Yet despite the promise of soaring demand driven by the energy transition, prices of rare earths have spiraled downward since 2022. A glut of Chinese supply is one problem. In recent years, Beijing has ramped up production of rare earths. In 2024, China ordered its state-owned miners to produce 135,000 metric tons of rare earths, up 13% from the quota in 2023.

At the same time, demand for rare earths hasn’t lived up to expectations. EV sales, for example, have slowed globally amid wavering consumer sentiment.

China’s overproduction, with its increasingly negative impact on industry profits, only makes sense as part of a broader economic strategy. The country produces 60% of the world’s mined rare-earth minerals. In recent years, it has also tightened its grip on the entire magnet supply chain: It controls 91% of refining activity, 87% of oxide separation and 94% of magnet production.

One theory is that Chinese overproduction is designed to stymie efforts to develop alternative sources of supply. Low prices of rare earths have squeezed margins for Western producers. This situation has long worried the West. The U.S., European Union, U.K., Canada and Australia have all drafted “critical mineral” strategies. To stand a chance of loosening China’s grip on rare earths, the West will need to deploy the country’s own tactics: unprofitable production and long-term thinking.

Classroom discussion questions:

What options do operations managers have with regard to the rare earth supply chain?
Will China’s strategy work?

OM in the News: Europe Is Embarking on a Mining Renaissance

Governments and companies around the world are scrambling to secure resources needed to power the energy transition, but some European countries are now thinking it may be better to look closer to home, reports The Wall Street Journal (Aug. 10, 2023). Copper, lithium, nickel, and rare earths are all key minerals crucial to powering wind turbines, electric vehicles and other clean tech, but largely have been imported from abroad in recent decades.

With demand for critical minerals surging, European governments want to exploit resources closer to home.

“No doubt there is a real demand story,” said a mining expert. “We are talking about a 35-fold increase in lithium demand and we do not have any large-scale lithium mines in Europe. It’s a massive problem.” But as governments fast-track approvals on such projects and struggle to convey the importance of efforts to secure materials for the green-energy transition, resistance is growing among locals who stand to feel an impact and environmentalists who urge caution when moving forward with projects in sensitive ecosystems.

In Germany, Vulcan Energy Resources is looking to open a lithium mine, harnessing a new technology for extracting the battery metal from brine. In Sweden, Copperstone Resources is hoping to reopen a brownfield mine site to extract the red metal, while Adriatic Metals has just started mining for silver and zinc in Bosnia, with more projects planned from Finland to Greece. In Portugal, Savannah Resources is planning to dig out one of Europe’s richest lithium deposits.

In Europe, the mining renaissance comes after years of nearly no new mining activity on the continent. Usually, opening a new mine takes 10 to 15 years, often because permitting can take years. Local backlash against new mines isn’t uncommon. The industry has a long history of environmental destruction, poor relations with local communities and deadly disasters. In 2021, local opposition derailed Rio Tinto’s lithium project in Serbia.

However, governments want and need a secure supply chain of metals and minerals. Most critical minerals are processed in a relatively small number of countries with the threat made more apparent last month after China said it would introduce export restrictions to germanium and gallium—two critical minerals used to make semiconductors. Prices skyrocketed as consumers were suddenly unsure if they would have the raw materials needed to make chips for cars, phones and other tech.

Classroom discussion questions:

What is China’s role/position in the rare earths and minerals supply chain?
What is the status of that supply chain in the U.S.?

OM in the News: China’s Dominance in the Rare Earth Supply Chain

The minerals, metals and rare earths needed for the green and digital transitions are shaping up to be the oil of this century—complete with a race to secure raw materials and production capacity at home or in friendly locations.

China has the early lead, writes The Wall Street Journal (March 9, 2023), dominating production of many critical materials including lithium and rare earths. Over the past years, China secured deposits around the world and invested heavily in the domestic manufacturing of clean technologies such as electric vehicles, batteries and solar panels. As the graph shows, China has a clear lead in the rare earth supply chain.

Western nations have now made it a top priority to secure a supply of these materials. The West has been tempted by the economic opportunity but also chastened by the recent semiconductor shortages, Europe’s efforts to replace Russian energy imports, and Beijing’s support for Russia after it invaded Ukraine.

Going back to President Trump, the U.S. signed executive orders for critical minerals– and has had recent success in starting to build local supply chains. The European Union’s latest effort—a Critical Minerals Act—aims to kick-start mining, processing and recycling in that region. There is one area where the EU act is right on the money—accelerating permitting. Permitting has been a key challenge for companies investing across geographies and sectors including mining, processing, power lines, solar, wind and batteries. In the EU, ambitious permitting reforms appears to be be the biggest hurdle to getting political agreement on that bloc’s local production of EV batteries. Limiting or overriding local opposition is rarely a vote-winning stance.

We may also get a G-7 critical minerals buyers club of the Group of Seven advanced democracies to secure supply from mineral rich countries in Africa, Asia and Latin America. Reduced Chinese supply—if it happens—will force Western policy makers and voters to face the trade-off between the carbon benefits of wind energy or electric vehicles and the environmental and pollution costs associated with manufacturing those technologies.

Classroom discussion questions:

Why are countries and companies so concerned about “rare earths”?
What is the main benefit in dominating the mineral supply chain?

OM in the News: The U.S.’s Supply Chain Review

The U.S. government is directing a broad review of supply chains for critical materials with the aim of spurring domestic production while strengthening ties with allies. As noted in our Feb. 18th blog, chip shortage is squeezing auto makers in the U.S. and world-wide. Cars use chips for numerous systems, including engine management, automatic braking and assisted driving.

The U.S. mandates a review of supply chains for four areas reports The Wall Street Journal (Feb. 25, 2021): semiconductors, used in products from cars to phones; large-capacity batteries used in electric vehicles; pharmaceuticals and rare-earth elements that are key to technology and defense, and supply chains covering six broader sectors, from technology to food production. Senators Rubio (R., Fla.) and Coons (D., Del.) recommended the government invoke the Defense Production Act to “incentivize or, if necessary, require American companies to retain their domestic capacities during this time.”

Bags of rare-earth concentrates at a California mine. China dominates the market for rare-earth elements.

The government intends to encourage domestic production with incentives such as job-training programs and business loans, in addition to using the federal procurement process for more American-made purchases. “This problem was decades in the making. We can solve it by making smart investments that are long term in nature,” said the National Economic Council. While China was not named directly, it dominates the rare-earths market and is a major player in other supply areas, including pharmaceuticals. “Right now, semiconductor manufacturing is a dangerous weak spot in our economy and in our national security. That has to change,” added Sen. Schumer.

A group of associations representing technology companies, the automotive industry and other businesses called for action to improve supply chains, including promoting the construction of semiconductor-manufacturing facilities and investing in research.

Classroom discussion questions:

What are the obstacles to revamping these “critical” supply chains?
Are the government incentives sufficient? What else can be done?

OM in the News: The Quest for Rare Earths Leads to Japan

Rare earth mining can be a dirty and ecologically damaging business. Here, a rare-earth metals mine in China.

“Japan has discovered hundreds of years’ worth of rare-earth metal deposits in its waters,” writes The Wall Street Journal (April 12, 2018). Why is this important? It reflects Tokyo’s concern about China’s hegemony over minerals used in batteries, x-rays, TVs, cell phones, electric vehicles, and 100s of other electronic devices.

The deposits were found about 1,150 miles southeast of Tokyo. Extracting them will be costly, but resource-poor Japan is pushing ahead in hopes of getting more control over next-generation technologies and weapon systems. A 965-square-mile seabed contains more than 16 million tons of rare-earth oxides, estimated to hold 780 years’ worth of the global supply of yttrium, 620 years’ worth of europium, 420 years’ worth of terbium and 730 years’ worth of dysprosium.

The U.S. Department of Energy and the E.U. have issued warnings about shortages of rare earths as China’s own consumption of them increases. “This is a game changer for Japan,” said an industry expert. “The race to develop these resources is well under way.”

In 2010, China pushed rare-earth prices up as much as 10 times by cutting its export quota on 17 rare earth elements by 40% from the previous year. It said it wanted to clean up a polluting industry, but the move left Japan and other nations seeking more independence from prices dictated by its neighbor. It is important for countries’ supply chains to secure their own source of resources, given how China controls the prices.

Classroom discussion questions:
1. Why are rare earths important to OM?

2. Where else can supply chain managers turn to procure these critical minerals?

OM in the News: Troubleshooting Intel’s Supply Chain in the Congo

American manufacturers have for years been under pressure from Congress to avoid buying “rare earths” and minerals from rebel held mines in the Congo. Government commanders and rebel militias in the Democratic Republic of the Congo earn about $185 million annually through the illicit trade of gold and so-called 3T minerals (tin, tantalum, and tungsten)—crucial elements in consumer electronics such as cell phones and tablets. The revenue has financed a brutal ongoing conflict resulting in the deaths of millions of innocent people. Intel no longer wanted to contribute to an economy of suffering. Just recently, reports FastCompany (April, 2015), Intel became the first company to build microprocessors entirely from conflict-free minerals.

But controlling the supply chain process at Intel was not at all simple. Identifying how conflict minerals entered its supply chain was key to eliminating them. Smelting plants, where raw ore is refined, offered one place to trace the origin of minerals, if only the facilities would comply with a transparent auditing process.

Over five years, Intel’s supply chain director, Carolyn Duran, and her team visited 91 smelters in 21 countries, using Intel’s purchasing power to put pressure on smelters to develop and implement an auditing system to track minerals so corporate buyers can source responsibly. The result: Nearly half the world’s 3T and gold smelters have now passed conflict-free audits, shrinking the market for illegally traded minerals and reducing warlords’ profits. Intel hopes to be able to declare its entire product line conflict-free by 2016, inspiring other firms to do the same.

Classroom discussion questions:

1. Why are rare earths critical to the supply chain and which countries supply them?

2. Why did Intel try to set this precedent?

OM in the News: China and its Rare Earths

China is home to most of the world’s deposits and almost all processing of the 17 minerals classed as rare earths — elements with uses ranging from iPhones to instrument panels to lasers. China’s 2011 quotas on rare earths exports– a shock to electronics manufacturers across the globe– have just been replaced with a resources tax, reports The Financial Times (Jan. 5, 2015). This eliminates its policy that caused friction with its trading partners and heightened awareness of their importance as strategic assets. The US recently won a challenge against the quotas at the World Trade Organization.

In some respects, China’s quota policy had been a success. Implemented at a time when its rare earths were exported cheaply and processed primarily in Japan, the price differential created by the quotas inspired many Japanese companies to move their plants to Inner Mongolia, one of the centers of rare earths mining in China.

But other goals of the quotas have not been successful: there has been little let-up in the environmental damage caused by rare earths mining and processing, and the pace at which they are mined has slackened little. The run-up in prices as quotas tightened also spurred funding for rare earths mining outside China, which had previously been unprofitable. The volatility in prices after China tightened quotas, has also led manufacturers to find other materials for applications, including magnets. That has alleviated some of the strategic concerns of China’s trading partners, which centered around the minerals’ importance to defense and high-tech industries.

Classroom discussion questions:
1. Why are rare earths so important in manufacturing?
2. When China disrupted supply lines in 2011, what did manufacturers do to adjust to shortages?

OM in the News: China’s Toxic Legacy From Its Rare Earths

A rare earth ingot is prized for its magnetic properties, but refining is a dirty process

Manufacturers of high tech products rely on a steady stream of 17 “rare earth” metals to make their goods. These lightweight, malleable minerals are essential to hybrid cars, cell phones, and disk drives. Rare earths had skyrocketed in price in the past a few years ago as China, the world’s dominant producer, unilaterally imposed taxes and annual tonnage limits on its exports. Lanthanum, for example, jumped from $4.5/lb to $73/lb. Neodymium surged from $9/lb to $207/lb and dysprosium from $243/lb to $1,135/lb.

But the Chinese export restrictions have become less important recently for two reasons, reports The New York Times (Oct.23, 2013). Alternative rare earth mines have gone into production in the US and Australia, reducing China’s share of global production to 85%, from 95% three years ago. And companies have become much more efficient about economizing on rare earths, especially the costliest ones, such as heavy rare earths like dysprosium. The global oil industry has similarly begun using less lanthanum during oil refining. Only 1.5% of the latest catalyst formulations for oil refining are now lanthanum, down from 4-5% three years ago.

Communities scattered across China face heavy environmental damage that accumulated through 2 decades of unregulated rare earth mining and refining. China’s recent white paper detailed environmental harm caused by the industry, and was used to try to justify the need for export restrictions. “Excessive rare earth mining has resulted in landslides, clogged rivers, environmental pollution emergencies and even major accidents and disasters, causing great damage to people’s safety and health and the ecological environment,” said the government report. Whole villages in Inner Mongolia have been evacuated and resettled elsewhere after reports of high cancer rates associated with the refineries there. A hazardous stew of toxic chemicals and low-level radioactive waste from refineries has been dumped into the world’s largest tailings pond, which covers 4 square miles near the Yellow River.

Classroom discussion questions:

1. Why are rare earths important in manufacturing?

2. Provide examples of products (not mentioned in the article) and their specific rare earths.

OM in the News: Why GE and Toyota Operations Managers Worry About “Rare Earths”

Here are 4 increasingly important manufacturing components you probably never heard of: (1) neodymium–used in magnets in wind turbines and Toyota Prius engines; (2) yttrium–used in wind-turbine blades and flourescent lamps; (3) lanthanum–used in batteries in hybrid cars and as a catalyst in gas and jet fuel; and (4) europium–makes the color red in TV, laptop, and iPhone screens.

As The Wall Street Journal (Sept. 12,2011) writes: “Manufacturers of high-tech products rely on a steady stream of metals–some of them scarce–to make their goods”. These “rare earth” metals, a collective name for 17 minerals used in products like these, have skyrocketed in price in the past 2 years as China (which controls 90% of global production) slashed exports to tighten control over the sector. Lanthanum, for example, jumped from $10/kg in 2009 to $160/kg today. Neodymium surged from $20/kg to $455/kg.

As a result, mining companies around the world, shut down by 20 years of cheap supply from China, are reopening. And companies like GE and Toyota are trying desperately to reduce or eliminate the need for the metals. GE, for example uses rhenium in engine blades. It has started experimenting with other hardening additives that are cheaper and more abundant. It has also started a global recycling program–pulling out old engines from scrap piles and dissolving them in acid baths to retrieve the scarce metal. Toyota is working with Tesla Motors to develop a new electric motor that does not use neodymium magnets.

Yet scientists have had little success in finding a replacement for the europium found in dozens of products from light bulbs to computer screens. This rare earth generates the color red, while terbium provides your iPhone’s green color.

Discussion questions:

1. Why are rare earths so important and now so rare?

2. How does an operations manager respond to changes in the supply chain such as these?

OM in the News: Recycling is a Necessity at Hitachi

Neodymium. You say you never heard of it? If you worked at Japanese firms Hitachi, Mitsubishi, Panasonic, or Sharp, your companies would be spending a lot of time trying to find this product, called a “rare earth”. Rare earths are light-weight, malleable metals that are essential to hybrid cars, cell phones, and hard disk drives. (Toyota Prius batteries use neodymium to power the car). Hundreds of other Japanese manufacturers also depend on them. And they had all counted on China, which produces 97% of the world’s supply of neodymium, dysprosium, didymium, and other rare earths, as the supplier.

But the latest issue of Businessweek (Jan.11,2011) describes how China has cut its exports of rare earths by over 3/4, driving up prices more than four-fold this past year. (Neodymium is now at $40/lb.) China wants to free up supplies for its own manufacturers, as well as reign in a very toxic industry.

So what is Hitachi doing ? The firm, which makes everything from nuclear power plants to home appliances to the Prius batteries, uses 600 tons of rare earths per year. The answer is recycling (Supp.5). Hitachi’s new facility in Matsudo City carefully saws open A/C compressors to retrieve rare earth magnets inside. It takes 2 workers 8 minutes to get to the prize inside each used air conditioner—4 wafer thin magnets containing 30 grams of rare earth metal. A separate conveyor belt feeds used disk drives into a massive machine, which pops out rare earth metal ready for harvesting. Other Japanese companies are following Hitachi’s lead in mining discarded products such as washing machines. The bottom line: China’s decision has prompted a whole new recycling industry.

Discussion questions:

1. Why did China cut its supply? What were its motives?

2. How might recycling of rare earths impact the world and its economy?

3. Why are rare earths so important and what other sources are going to be available?