Familiar to us as the black substance in charred wood, as diamonds, and the graphite in “lead” pencils, carbon comes in several forms, or isotopes.
Carbon has unique properties that are essential for life on Earth.
"Everything which has come down to us from heathendom is wrapped in a thick fog; it belongs to a space of time we cannot measure.
We know that it is older than Christendom, but whether by a couple of years or a couple of centuries, or even by more than a millenium, we can do no more than guess." [Rasmus Nyerup, (Danish antiquarian), 1802 (in Trigger, 19)].
C has not actually disappeared, it has simply moved out of the atmosphere.
The temporal variations of artificially high levels of atmospheric radiocarbon have been captured in organic material world-wide and thus offer an opportunity to determine a date of synthesis for biomolecules.