High resolution TEM micrograph (HRTEM) of presolar nanodiamonds from the Allende meteorite, showing nanodiamonds dispersed on an amorphous carbon support film. The only visible periodic rows of atoms are from diamond {111} planes with d-spacing = 0.206 nm. The crystal near the center has a five-fold twin structure characteristic of isotropic growth conditions in chemical vapor deposition processes. (Photo courtesy of T. L. Daulton).