Black Diamond Engagement Rings are very much in fashion. Apart from their obvious beauty, Black Diamonds are much cheaper than other diamonds, giving you a larger stone for your money! There are two types of black diamonds.; naturally occurring Black Diamonds are the result of high numbers of inclusions, usually tiny particles of graphite. This makes them rather fragile and liable to fracture, a challenge to cut and polish. Black diamonds seen in jewelry are mostly enhanced white diamonds treated with radiation in order to change their appearance.