What Do “The 4 Magnetic Rare Earths” Mean?

Recent supply-chain headlines have made the phrase “the 4 Magnetic Rare Earths” much more visible than before. A recent Reuters report on the Serra Verde and USA Rare Earth deal used this wording for the four major rare earths needed to make permanent magnets, and the companies themselves have used very similar language in their own announcements around the transaction.

In most cases, the 4 Magnetic Rare Earths refers to neodymium (Nd), praseodymium (Pr), dysprosium (Dy), and terbium (Tb). This expression is mainly used in the context of the Neodymium magnet supply chain, where these four elements carry most of the strategic attention, commercial value, and technical discussion. S&P Global also uses “magnetic rare earths” to refer specifically to Nd, Pr, Dy, and Tb.

The phrase is appearing more often because the market is no longer talking only about magnets in a technical sense. It is now talking about supply security, export controls, project finance, offtake agreements, and mine-to-magnet strategies. Once that happens, the conversation naturally narrows toward the rare earth elements that matter most to high-performance permanent magnets.

That is exactly why recent reporting around Serra Verde received so much attention. Reuters described the deal as covering the four major rare earths needed to make permanent magnets, while USA Rare Earth highlighted Serra Verde as the only scaled producer outside Asia of all four magnetic rare earth elements. Serra Verde’s own materials also emphasize Nd, Pr, Dy, and Tb as the rare earths most in demand because they are used together in permanent magnet applications.

Neodymium and praseodymium are the core rare earth inputs behind most Neodymium magnet production. In market language, they are often grouped together as PrNd, because they are closely linked in both supply-chain discussions and pricing. Reuters referred to PrNd as two commonly used rare earths in the same Serra Verde coverage.

Dysprosium and terbium receive extra attention because they are the heavy rare earths most closely tied to higher-temperature magnet performance. The U.S. Department of Energy notes that sintered Neodymium magnets can contain small additions of Dy or Tb to improve resistance to demagnetization at higher temperatures, while S&P Global noted that Dy and Tb are especially important where magnets must operate at elevated temperatures, including in hybrid and electric vehicle applications.

Put simply, when people in mining, refining, policy, or investment circles say “the 4 Magnetic Rare Earths,” they usually mean the four rare earth elements most central to the commercial and technical value of the Neodymium magnet chain: Nd, Pr, Dy, and Tb.

These four matter because not all rare earth elements play the same role in the magnet business. Some are more visible in ore bodies or separation flows, but Nd, Pr, Dy, and Tb are the ones most directly associated with the magnet materials that support electric vehicles, wind turbines, electronics, defense systems, and other high-value applications. Serra Verde explicitly states that these four rare earths are expected to be most in demand because they are used together in permanent magnets for aerospace, defence, automotive, electronics, and energy applications.

S&P Global went even further, citing McKinsey data that magnetic rare earths account for only about 30% of total rare earth element volumes but more than 80% of market value. That helps explain why so much capital, policy attention, and media coverage now centers on this smaller group of elements rather than on the full rare earth family as a whole.

A big reason is simple: the global market has been reminded how concentrated this supply chain still is. Reuters reported in April 2026 that China accounts for about 90% of global processed rare earth output, while a separate Reuters explainer in October 2025 said China produces over 90% of the world’s processed rare earths and rare earth magnets.

At the same time, China tightened controls in 2025. Reuters reported that China added seven medium and heavy rare earth elements and magnets to its export control list in April 2025, and later tightened rules further in October. Reuters also noted that the earlier round of controls caused shortages of rare earth magnets and pushed foreign producers and governments to accelerate diversification efforts.

That does not mean supply chains outside China are already mature. It means they have become more active, more urgent, and more heavily funded. S&P Global reported that governments and investors in the U.S., Canada, Australia, and elsewhere are pouring money into rare earth projects to counter China’s market position, while Reuters and USA Rare Earth’s own release show how offtake structures, price floors, and government-backed financing are now being used to support projects such as Serra Verde.

The phrase “the 4 Magnetic Rare Earths” is useful, but it should not be treated as a complete textbook definition of all rare earth use in permanent magnets. In practice, it is a supply-chain shorthand that is most closely tied to the Neodymium magnet discussion, especially when the market is focused on resource quality, separation value, heavy rare earth access, and non-China project development. That is also why USA Rare Earth’s release described these as the four magnetic rare earths required to make a Neodymium magnet.

So when you see this term in recent news, the safest interpretation is not “these are the only rare earths that matter,” but rather: these are the four rare earth elements that currently attract the most attention in the Neodymium magnet supply chain and in efforts to build alternative magnet material supply outside China.

For readers outside the mining and policy world, magnetic rare earths may sound like a new technical term. In reality, it is better understood as a practical industry shorthand. Today, it usually points to Nd, Pr, Dy, and Tb — the four rare earth elements most closely associated with the value, performance, and supply-chain risk of modern Neodymium magnets.

And that is exactly why the phrase is becoming more common now. As export controls, government funding, and non-China projects reshape the conversation, the market is paying closer attention not just to “rare earths” in general, but to the specific rare earth elements that matter most to magnet production.