A group of Californian researchers suggests that the most compact element is not in jewelry, but at the ends of some pens and needles. New measurements indicate that the most compact natural element is osmium. Researchers at the Livermore National Laboratory have measured the compressibility of osmium and have found that it is much lower than announced by theoretical calculations.
Being a metal, the small compressibility of osmium has surprised researchers. Diamond atoms are united in a very compact and special way, but in metals the bond between atoms is weaker. However, and being more resistant to plating, the diamond will not lose the title of the hardest element.