the.com/lutetium
The last lanthanide, named after Paris and so rare nobody bothered to use it.
name originLutetia, the ancient Roman name for Paris
discovery feudThree chemists claimed it independently in 1907
hardest lanthanideDensest and hardest of all rare earths
barely usefulAlmost no commercial applications despite full research
atomic ageUsed to date meteorites and Earth's oldest rocks