a round, pure-carbon fullerene, C, with a structure similar to that of a geodesic dome
See buckminsterfullerene in American Heritage Dictionary 4
(bŭkˌmĭn-stər-fo͝olˈə-rēnˌ)
noun
An extremely stable, ball-shaped carbon molecule, C60, reminiscent of a geodesic dome, and believed to occur naturally in soot. It was the first fullerene to be discovered.