Nd, Pr, Dy, Tb: A Rare Earth Periodic Table for Investors

Not all rare earths are created equal. Neodymium trades around US$73 per

kilogram while terbium commands over US$1,000. A working understanding

of which elements sit where — and why — is essential for reading any

rare-earth project's economics.¹

The Basic Chemistry

The rare-earth elements are 17 metallic elements: the 15 lanthanides

(from lanthanum through lutetium), plus yttrium and sometimes scandium.

They are chemically similar to each other but differ enough in atomic

radius and electronic structure to produce materially different

industrial properties. Industry practice typically groups them into two

families: light rare earths (LREEs) — lanthanum, cerium, praseodymium,

neodymium and samarium — and heavy rare earths (HREEs) — europium,

gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium,

lutetium, plus yttrium.

The light-heavy divide matters commercially because heavy rare earths

are typically less abundant in natural deposits, harder to separate, and

more valuable in the applications that drive current demand growth. The

2025 USGS price table makes the separation visible in dollar terms.¹

The Light Rare Earths

Lanthanum and cerium are the workhorses. Lanthanum oxide traded at

roughly US$1.00 per kilogram in 2025; cerium oxide at US$1.71 per

kilogram.¹ Both are used in catalysts — particularly for petroleum

refining and automotive emissions — and in glass polishing, ceramics and

specialty alloys. Their economic role is high volume and low margin, and

their prices are relatively stable because global supply is abundant.

Praseodymium and neodymium are where the magnet demand concentrates on

the light side. Praseodymium oxide traded at US$74 per kilogram in 2025

and neodymium oxide at US$73 per kilogram. The combined

neodymium-praseodymium (NdPr) oxide, sold as a mixed product, traded at

US$69 per kilogram.¹ These two elements are the principal ingredients in

NdFeB permanent magnets used in electric vehicles, wind turbines and

defence systems. Their demand growth underpins most of the rare-earth

market's forward value.

Samarium sits slightly to the side. Samarium oxide traded at US$2.82 per

kilogram in 2025 — higher than La/Ce but well below Nd/Pr.¹ Samarium is

used in samarium-cobalt magnets, a specialty high-temperature magnet

alloy particularly relevant to defence applications, and in some

nuclear-industry niche uses.

The pricing relationship between the light rare earths has been

unusually volatile over the past five years. Neodymium-praseodymium

prices swung between roughly US$55 per kilogram in 2024 and peaks above

US$130 per kilogram during the 2021-2022 energy-transition demand spike.

The 2025 settled level of US$69 per kilogram sits in a middle band,

reflecting improved supply plus moderated speculative positioning.

The Heavy Rare Earths

The heavy rare earths are where the price action gets interesting.

Europium oxide traded at US$27 per kilogram in 2025, gadolinium oxide at

US$30 per kilogram.¹ Europium is used in red phosphors for displays (a

use that has declined with LED substitution) and in control rods;

gadolinium is used in medical imaging contrast agents and specialty

alloys.

Dysprosium and terbium sit at the top of the price table. Industry

reporting during 2025 placed dysprosium at roughly US$250 per kilogram

and terbium above US$1,000 per kilogram.² Both are added to

neodymium-iron-boron magnets to maintain magnetic performance at high

temperatures — a critical capability in EV drive-motors and

defence-grade actuators.

The remaining heavy rare earths — holmium, erbium, thulium, ytterbium,

lutetium — are used in smaller volumes for specialty optics, fibre-optic

amplifiers, laser crystals and certain niche medical applications. They

carry meaningful prices but in smaller commercial markets than the

magnet-related heavies.

China's October 2025 expansion of export controls covered precisely

these smaller-volume heavy elements — holmium, erbium, thulium, europium

and ytterbium — alongside the April list. The inclusion reflected

Chinese concerns about their defence and electronics applications, not

their commercial volume. For most Western buyers, the October additions

hit demand for specialty applications more than mass-market products,

but the strategic message was significant nonetheless.

Yttrium, Scandium — The Adjacent Elements

Yttrium is technically not a lanthanide but sits alongside them in

commercial rare-earth treatment because of similar chemistry and

extraction practices. It is used in phosphors, specialty alloys, laser

crystals and some ceramic applications. Its price sits in a middle

range, and its production tends to be tied to other heavy-rare-earth

recovery.

Scandium is even further from the lanthanides chemically but is often

treated alongside rare earths in market commentary because of similar

supply-chain dynamics. It is used in specialty aluminium-scandium alloys

— including in certain aerospace and defence applications — and trades

at high per-kilogram prices driven by very limited supply rather than

high volume demand.

Why the Magnet Four Matter Most

For investors looking at rare-earth projects, the single most important

question is the project's rare-earth distribution — specifically, the

share of neodymium, praseodymium, dysprosium and terbium in total

contained rare earths. These four elements, sometimes called the "magnet

four," account for the overwhelming majority of the revenue potential in

most contemporary rare-earth deposits.

A deposit with 30 percent magnet-four share and 70 percent

everything-else has very different economics from a deposit with 10

percent magnet-four and 90 percent everything-else, even if total

rare-earth content is identical. Brazilian ionic-clay projects typically

have higher magnet-four shares than traditional bastnaesite operations,

which is part of what makes them economically competitive against much

larger carbonatite-hosted producers.

Adamas Intelligence's public research has emphasised that dysprosium and

terbium oxides in particular face sustained undersupply through 2040 —

roughly 1,800 tonnes and 450 tonnes of annual deficit respectively at

projected demand levels.³ Projects with heavy-rare-earth exposure

therefore sit in structurally attractive parts of the commodity complex.

Outlook

The rare-earth basket is not homogeneous. A project's economics depend

on which elements it carries and in what proportions, and a diversified

investor view needs to weight exposures accordingly. For Brazilian

rare-earth producers, the current market environment rewards the

specific fractional composition that ionic-clay deposits carry — strong

neodymium-praseodymium share, meaningful dysprosium and terbium, less

dependence on hard-to-monetise light elements. Over time, as the market

matures and prices normalise across the complex, that relative advantage

may narrow. For the immediate decade, however, the perio

Related:
All rare earth articles | Brazil Critical Minerals | Brazil Mining Journal