Carbon flaw

Blemish in diamond crystalline form of carbon

A carbon flaw is a blemish present within a diamond crystalline form of carbon, usually seen as a black spot. The blemish may be microscopic or visible to the naked eye. The spots are undesirable imperfections since they can be seen more easily than other flaws. It is worth noting that, while diamonds are composed of purely carbon, the black spot flaws could be other inclusions such as olivine, garnet, pyrite, silica, calcite, and iron oxides.

This keyword could refer to multiple things. Here are some suggestions: