Lutetium is a soft and ductile, silvery metal. It is one of the less reactive of the rare earth metals. Lutetium reacts with water, but slowly, and even more slowly with oxygen. As such, lutetium resists corrosion in dry air, but not in moist air. With the highest density, melting point, and hardness of the lanthanides, it is the last element in the lanthanide series.
The rarest of the rare earths, lutetium is found in very small amounts with other rare-earth metals. This makes pure lutetium metal one of the most expensive of the rare earth metals to prepare.
Hazards: Even though lutetium is regarded as having a low degree of toxicity the compounds should still be handled with care. Lutetium in forms with a high surface area such as powder and thin foils may be flammable when exposed to spark or another ignition source.