Black diamonds are a gem highly prized by designers today. Discovered in 1840 in Brazil, black diamonds were first used for industry. It was only at the beginning of the 20th century that the world of jewelry became interested in this atypical stone full of mysteries. Called carbonado by Brazilians, this stone strongly resembles diamonds, but some differences remain. Unlike “normal” diamonds, carbonado are not monocrystalline. They are formed from an aggregate of several crystals: diamond, graphite and hematite and have a porous appearance. Of the same hardness as diamonds, 10 on the Mohs scale, they are more difficult to cut since they do not have a cleavage plane (weakness of structure which facilitates cutting). This difficulty leads to large losses during cutting (up to 50% of the gross weight can be lost to arrive at a cut stone).
Origins still unknown “Normal” diamonds formed in the Earth's mantle and rose to the surface through volcanic eruptions through rocks like kimberlite. On the other hand, there is no trace of kimberlite in black diamonds. The origin of these black stones is still poorly known but several theories exist. The most plausible seems to be that they have an extraterrestrial origin. Indeed, we observe that black diamonds were formed in an environment rich in hydrogen, that is outside the solar system. Their creation would result from a supernova, that is to say the implosion of a star. The luminescence of black diamonds shows that radioactive elements took part in the formation process. The main deposits are still in Brazil but also in the Central African Republic. Used as gems, there are today, as for white diamonds, carbonados treated by heating or irradiation.
The mysterious and bewitching aspect of this stone has attracted the attention of many creators. Jeweler Bare uses black diamond brilliancy to pave his Kite earring. Rivka Nahmias uses barely cut black diamond beads to create a rock and discreet yellow gold bracelet. Alessa Jewelry perfectly mixes white and black diamonds revealing a contrasting pendant. Hoorsenbuhs, meanwhile, bets on the total black look with his Phantom ring in black gold and set with black diamonds. Finally, the world of piercing is no exception to this trend: Maria Tash sublimates the ears with her white gold piercing jewelry, set with black and white diamonds.
