Symbol

Lu

Atomic Number

71

Atomic Mass

174.97

Family

Lanthanide (Rare Earth Metal) Pronunciation

loo-TEE-she-um

Overview

Lutetium is the heaviest, rarest, and most expensive lanthanide element. The lanthanide elements make up Row 6 of the periodic table. The periodic table is a chart that shows how chemical elements are related to one another. The lanthanides are pulled out into a separate row at the bottom of the table. They are also called the rare earth elements. That name does not fit very well for most lanthanides. They are not really so rare, only difficult to separate from each other. However, lutetium is both rare and difficult to separate from the other lanthanides.

Lutetium was first discovered in the early 1900s by two chemists working independently. It was found in a complex black mineral that had been found near the town of Ytterby, Sweden, in 1787.

Today, there are very few uses for...