Element 71 · Lanthanide (Rare Earth)
Lutetium
Lutetium is the densest, hardest, and most expensive of the lanthanides — used in PET medical imaging.
Element Facts
SYMBOL
Lu
ATOMIC NO.
71
ATOMIC WEIGHT
174.97
CATEGORY
Lanthanide (Rare Earth)
PERIOD
Period 6
GROUP
Group 3
Discovery & History
Lutetium was the last of the natural lanthanides to be isolated and was discovered simultaneously in 1906–1907 by Georges Urbain in Paris (naming it “lutetium” after Lutetia, the Roman name for Paris) and Carl Auer von Welsbach in Vienna (who called it “cassiopeium”). The IUPAC confirmed lutetium in 1949. Although extremely rare and expensive, lutetium-177 has emerged as a highly effective targeted radiotherapy agent for neuroendocrine tumours.
Quick Overview
Lutetium is element 71, the final lanthanide. It has the highest density and hardness of any lanthanide. Lutetium oxyorthosilicate (LSO) crystals are central to modern PET (positron emission tomography) cancer scanners.
Where It's Used
LSO scintillator crystals in PET scanners. Lutetium-177 isotope for targeted radiotherapy of neuroendocrine tumours. Petroleum cracking catalysts.
Can You Sell It?
Why QuickStop Metals doesn’t buy Lutetium:
Lutetium has tiny global production volumes (around 10 tonnes per year) and goes entirely to specialist medical and chemical applications. No general scrap market.
Price Guide
Lutetium oxide trades at approximately £400–900/kg, among the most expensive of the stable rare earths due to its low abundance in ore deposits. Not a scrap yard material.