A “Black Diamond” is a natural polycrystalline aggregate of minute graphite and carbon crystals grown together at different angles which causes them to absorb the light. They are 4 billion years old, formed in a supernova explosion long before our Solar System was born and found only in a few places on Earth, notably Central Africa and Brazil
Carbonados are opaque with a dark grey exterior. Their surface is usually porous, allowing a black dye to penetrate. Carbonados are commonly dyed by being boiled in spent motor oil to make their grey surfaces appear black.
There are two types of black diamonds: natural diamonds treated by irradiation, or a combination of a strong radioaction and extreme heat that darkens the stone’s color. Black diamonds are cheap by diamond's standards, they cost much less than white diamonds.
Without the dye, most carbonados bear an eerie resemblance to marcasite - polished iron pyrite commonly used in costume jewelry.
In the past, black diamonds were corted out for industrial use such as manufacturing abrasives and drill bits.
Fast forward to modern times where the growing population has an insatiable appetite for anything titled “a diamond.” Be it a credit card or an escort service.
Due to Carbonado unique chemistry that suggests extraterrestrial origins, they became a good marketing tool in the hands of the inventive diamond industry. Although they are technically nearly worthless, the mysterious origin played well to the ears of consumers.
Along with petrified dinosaur dung and wall-mounted singing fish, they’ve become a treasured collectible novelty that is cheap and named well. Additionally, carbonado exhibit strong luminescence (or the ability to emit light in the darkness), which is always fun at a party.