Yes, there is a black variety of diamond, found in Brazil, that is used for diamond drills. It occurs in irregular or rounded fragments, rarely distinctly crystallized, with a texture varying from compact to porous.
Some of the denser, less flawed black diamonds can be polished, but usually the stones produced have badly flawed surfaces. In addition, many of them are flecked with gray or dark gray rather than being completely black and they are not generally thought to be that attractive.
Black diamonds are very rare and the colour is produced by tiny pieces of magnetite and haematite minerals that have become captured within the carbon lattice structure of the diamond.
A famous black diamond called the Black Orlov diamond was in the Russian nobility and it was supposed to be cursed. Several of its owners met very violent deaths, fuelling the legend.
Some of the denser, less flawed black diamonds can be polished, but usually the stones produced have badly flawed surfaces. In addition, many of them are flecked with gray or dark gray rather than being completely black and they are not generally thought to be that attractive.
Black diamonds are very rare and the colour is produced by tiny pieces of magnetite and haematite minerals that have become captured within the carbon lattice structure of the diamond.
A famous black diamond called the Black Orlov diamond was in the Russian nobility and it was supposed to be cursed. Several of its owners met very violent deaths, fuelling the legend.