Meteroites carbon dating
Carbon as an element was discovered by the first person to handle charcoal from fire.
Thus, together with sulfur, iron, tin, lead, copper, mercury, silver, and gold, carbon was one of the small group of elements well known in the ancient world.
Diamond and graphite occur naturally on Earth, and they also can be produced synthetically; they are chemically inert but do combine with oxygen at high temperatures, just as amorphous carbon does.
Fullerene was serendipitously discovered in 1985 as a synthetic product in the course of laboratory experiments to simulate the chemistry in the atmosphere of giant stars.
Q-carbon, which is created by rapidly cooling a sample of elemental carbon whose temperature has been raised to 4,000 K (3,727 °C [6,740 °F]), is harder than diamond, and it can be used to manufacture diamond structures (such as diamond films and microneedles) within its matrix. Each of the “amorphous” forms of carbon has its own specific character, and, hence, each has its own particular applications.
All are products of oxidation and other forms of decomposition of organic compounds.
The primary source of diamonds is a soft bluish peridotic rock called kimberlite (after the famous deposit at Kimberley, South Africa), found in volcanic structures called pipes, but many diamonds occur in alluvial deposits presumably resulting from the weathering of primary sources.
(Coals are elemental carbon mixed with varying amounts of carbon compounds.
Coke and charcoal are nearly pure carbon.) In addition to its uses in making inks and paints, carbon black is added to the rubber used in tires to improve its wearing qualities.
Isolated finds around the world in regions where no sources are indicated have not been uncommon.
Natural deposits are worked by crushing, by gravity and flotation separations, and by removal of diamonds by their adherence to a layer of grease on a suitable table.
However, carbon compounds (i.e., carbonates of magnesium and calcium) form common minerals (e.g., magnesite, dolomite, marble, or limestone).