Osmium is Forever: Rare metal’s strength humbles mighty diamond’s

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.)