Facts on carbon dating
An extremely rare allotrope of carbon, lonsdaleite, has been calculated, in pure form, to be 58% stronger than diamond.
The buckyballs arrived in comets or asteroids and have been discovered in rocks associated with the Permian-Triassic mass extinction 250 million years ago. A wonderful image released by Michael Ströck under the GNU Free Documentation License: The structures of eight allotropes of carbon: a) Diamond b) Graphite c) Lonsdaleite d) C60 (Buckminsterfullerene) e) C540 Fullerene f) C70 Fullerene g) Amorphous carbon h) Single-walled carbon nanotube. Harmful effects: Pure carbon has very low toxicity.
Inhalation of large quantities of carbon black dust (soot/coal dust) can cause irritation and damage to the lungs.