Diamonds that are colored black can be “natural” called Natural Fancy Black Diamonds or they can be “enhanced” or treated and called Black Diamonds. Both are real diamonds.
Black diamonds are enhanced (heated) diamonds using processes such as HTHP, whereas Natural Fancy Black Diamonds are as they were when they were found in the rough and this makes them appealing and valuable.
Natural Black diamonds come in only one color intensity, Fancy Black, and are considered to be opaque, getting their color from the presence of graphite which is clustered randomly throughout the diamond. Black diamonds have become quite popular in recent years for use in jewelry including rings, bracelets and studs. Celebrities seem to be drawn to them.
Natural Fancy Black Diamonds can be quite affordable depending upon their size, however when compared with Black Diamonds, the per-carat cost can be at least ten times greater.