Lutetium metal is the last of the lanthanides, the hardest of them, the one with the smallest atomic diameter, the rarest stable metal after thulium metal and the one which is most difficult to extract.
Therefore Lutetium metal is rather expensive and it's scarcely used.
Curiosity: the natural occurring, radioactive 176Lu, which has a half-life of 38 billion years, is used to determine the age of meteorites.
High purity Lutetium metal shiny sample piece placed in argon sealed ampoule and labeled glass vial. Pure and shiny Lutetium Metal for element collection.
Dimensions of the ampoule: 40x12mm approx.