Even top-caliber diamonds aren’t perfect. And their imperfections are finally settling a debate about the origins of the gem-quality diamonds used in jewelry.
Previously, scientists had an explanation only for how cloudy and impurity-ridden fibrous diamonds form. Those diamonds crystallize inside fluid pockets deep within the Earth that contain compounds called carbonates. Carbonate-containing impurities inside fibrous diamonds provide information about the diamonds’ origins. Gem diamonds typically don’t contain these impurities, so scientists argued over whether the gems formed under different conditions than fibrous diamonds.