Gadolinium

Gadolinium is a silvery lanthanide with remarkable magnetic properties, it is one of the few lanthanides that becomes strongly magnetic near room temperature. Most importantly, gadolinium-based contrast agents are injected during MRI scans to enhance the visibility of blood vessels and tumours.

• Atomic Number6464 protons, 64 electrons
• Atomic Mass157.25 u64× heavier than hydrogen
• State at Room TempSolidSolid
• Density7.90 g/cm³
• Melting / Boiling1312.8°C / 3272.8°C
• Discovered1880

What is Gadolinium?

Gadolinium is a lanthanide rare earth metal with 64 protons. Gadolinium compounds injected before MRI scanning shorten the relaxation times of nearby water protons, creating contrast between different tissues. Gadolinium neutron absorbers are used in control rods of some nuclear reactors. Named after the Finnish chemist Johan Gadolin (1760-1852), who first studied yttrium-group elements.

Fact Gadolinium is element 64 in the periodic table, symbol Gd. As a lanthanide, it is part of the group of 15 elements sharing very similar chemistry, formed by the filling of the 4f electron subshell. All lanthanides form stable +3 ions and are found together in rare earth mineral deposits.

Where you find Gadolinium

On Earth

Gadolinium is found alongside other rare earth elements in minerals such as monazite, bastnäsite and xenotime. China produces the vast majority of world supply, with smaller contributions from Australia, the United States, Russia and India. It is never found as a free metal in nature.

• Monazite and bastnäsite. The primary rare earth minerals that contain Gadolinium.
• Ion-adsorption clays. Certain clay deposits in southern China are particularly rich in heavier lanthanides including Gadolinium.

How we use Gadolinium

Gadolinium compounds injected before MRI scanning shorten the relaxation times of nearby water protons, creating contrast between different tissues. Gadolinium neutron absorbers are used in control rods of some nuclear reactors. Named after the Finnish chemist Johan Gadolin (1760-1852), who first studied yttrium-group elements.

Did you know? Gadolinium was one of the last lanthanides to be isolated in pure form. The extraordinary chemical similarity between adjacent lanthanides made separation extraordinarily difficult until ion exchange chromatography was developed in the 1940s.

How it was discovered

Gadolinium was identified and separated from the mixture of rare earth elements found in minerals from Ytterby, Sweden and other locations, through painstaking fractional crystallisation and spectroscopic analysis over many decades in the 19th century.

Deeper dive: gadolinium and rare earth supply chains

The lanthanides, often called rare earth elements, are critically important for clean energy technologies. Neodymium and praseodymium go into the powerful magnets in EV motors and wind turbines. Dysprosium improves those magnets at high temperatures. Lanthanum and cerium go into NiMH batteries, catalysts and glass. Europium and terbium provide red and green in LED phosphors. This means that the global transition to clean energy depends heavily on rare earth elements, and their supply is dominated by China, which produces over 60% of the world's rare earth output. Concerns about supply security have spurred investment in rare earth mining projects in Australia, Canada, the USA and elsewhere.

Moving to 65 protons brings us to the next element on the periodic table.