What is Carbon?

1. Carbon is an element. Diamond, graphite, and carbon black are all carbon; the carbonates, like calcite, contain some carbon in combination with other elements. 2. In the trade, carbon is an abbreviation of carbonado.  
Black inclusions in diamonds are called carbon spots, although, as Eric Bruton, observes, very few if any are carbon, and only a few are truly black. The black look comes from the reflection of light by cleavages or by colorless, transparent included diamond crystals, the true nature of which is seen when the stone is examined under magnification in dark-field lighting.
Many carbon spots can be made less conspicuous by laser drilling and solution.

Diamond Carbon Element - A Definition Peters Vaults Jewelry Glossary