Osmium is Forever: Rare metal’s strength humbles mighty diamond’s
By Peter Weiss
In a surprising overturn, the lustrous, blue-white element osmium has beaten diamond in a test of compressibility. Not used much today, osmium has been incorporated into alloys for fountain-pen tips and phonograph needles.
Diamond still reigns as the hardest of materials. However, the finding that osmium is actually the high-pressure champ may open up new routes to materials that may someday surpass diamond in hardness, says Hyunchae Cynn of Lawrence Livermore (Calif.) National Laboratory.
“It’s stunning that such an incompressible element is only now recognized,” says Raymond Jeanloz of the University of California, Berkeley. “The additional surprise is that a metal could be so incompressible.”