Stanford and SLAC National Accelerator Laboratory jointly hurry the world's leading program for isolating and studying diamondoids—the tiniest possible specks of diamond. Found naturally in petroleum fluids, these interlocking carbon cages weigh less than a billionth of a billionth of a carat (a carat weighs approximately the same as 12 grains of rice); the smallest ones contain just 10 atoms.
Source: phys.org