black diamond

Noun

 * 1) hematite
 * 2) anthracite
 * 3) carbonado, a natural diamond that is black in colour
 * 4) A black synthetic diamond, specifically a CVD polycrystalline diamond or HPHT polycrystalline compact diamond.
 * 5) boron carbide
 * 6)  A member of the new affluent black middle class in South Africa, characterized by conspicuous consumption.
 * 7)  A symbol representing a steep and relatively difficult trail, typically 40% gradient or above.