Lutetium

Lutetium is the heaviest and hardest of the lanthanides. It is used in PET scanner detectors, as a catalyst in petroleum refining, and in a promising cancer treatment called lutetium PSMA therapy that delivers radioactive lutetium directly to prostate cancer cells.

• Atomic Number7171 protons, 71 electrons
• Atomic Mass174.9667 u71× heavier than hydrogen
• State at Room TempSolidSolid
• Density9.84 g/cm³
• Melting / Boiling1662.8°C / 3401.8°C
• Discovered1907

What is Lutetium?

Lutetium is a lanthanide rare earth metal with 71 protons. Lutetium oxyorthosilicate (LSO) crystals doped with cerium are used as scintillators in PET (positron emission tomography) scanners. Lutetium-177 bound to prostate-specific membrane antigen (PSMA) is a targeted radiotherapy for prostate cancer. Named after Lutetia, the Latin name for Paris.

Fact Lutetium is element 71 in the periodic table, symbol Lu. 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 Lutetium

On Earth

Lutetium 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 Lutetium.
• Ion-adsorption clays. Certain clay deposits in southern China are particularly rich in heavier lanthanides including Lutetium.

How we use Lutetium

Lutetium oxyorthosilicate (LSO) crystals doped with cerium are used as scintillators in PET (positron emission tomography) scanners. Lutetium-177 bound to prostate-specific membrane antigen (PSMA) is a targeted radiotherapy for prostate cancer. Named after Lutetia, the Latin name for Paris.

Did you know? Lutetium 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

Lutetium 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: lutetium 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 72 protons brings us to the next element on the periodic table.