Carbon dating diamonds
Carbon is unique in its chemical properties because it forms a number of components superior than the total addition of all the other elements in combination with each other.The biggest group of all these components is the one formed by carbon and hydrogen.Elemental carbon exists in two well-defined allotropic crystalline forms: diamond and graphite.Other forms with little crystallinity are vegetal carbon and black fume.Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. 1979, 1986 © Harper Collins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 Cite This Source A nonmetallic element occuring in many inorganic and in all organic compounds, existing as graphite and diamond and as a constituent of coal, limestone, and petroleum, and capable of chemical self-bonding to form a number of important molecules.Atomic number 6; atomic weight 12.01115; sublimation point above 3,500°C; melting point 3,550°C; specific gravity of amorphous carbon 1.8 to 2.1, of diamond 3.15 to 3.53, of graphite 1.9 to 2.3; valence 2, 3, 4.The most prized specimens for research are flawed with visible inclusions (figure 2), for these carry actual samples of mantle minerals from depths as great as 800 km beneath the surface.
Humans have been aware of carbon since the earliest of times. The black color of smoke is caused by unburned specks of carbon. It occurs in more different forms than any other element in the periodic table.The periodic table is a chart that shows how chemical elements are related to each other.Research into natural diamonds (figure 1) has emerged over the last two decades as one of the keys to understanding the deep earth.Analytical advances, improved geologic knowledge, and the emergence of new diamond-producing regions (such as the Slave craton of Canada) have all contributed to this change.