Older gems, younger crystals both formed under similar conditions deep within Earth, trapped carbonates suggest
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.
After an exhaustive hunt, geochemists have at last found microscopic impurities within gem-quality diamonds. These flaws suggest that pretty and ugly diamonds form from the same kinds of carbonate-containing fluids, the researchers report in the June