Although fullerenes--spherical molecules made entirely of carbon--were first found in the laboratory, they have since been found in nature, formed in fissures of the rare mineral shungite
Since laboratory synthesis of fullerenes requires distinctive conditions of temperature and pressure, this discovery should give geologists a test case for evaluating hypotheses about the state of the Earth' s crust at the time these naturally occurring fullerenes were formed
Some fullerenes have also been found on the remains of a small meteorite that collided with a spacecraft.