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.
Strike at Freeport's giant Peru mine takes offline world's three biggest mines, but worries about demand drops copper after huge jump in warehouse stocks.