The company expects demand to increase 3% this year, while no new mines are scheduled to come online in the short-term and supply disruptions continue.
Disputes at BHP Billiton’s Escondida mine in Chile, the world's biggest copper mine, and Freeport’s Grasberg and Cerro Verde mines, are also having a significant effect on global supplies of concentrate.
The rectangular, 25.27-carat gem is one of a collection of 13 polished diamonds cut from the famous 726-carat Jonker rough, unearthed at South Africa’s Elandsfontein mine in 1934.