The miner said it remains cautious about the state of the global market for both rough and polished diamonds, noting that financing challenges persist.
Project will extend the life of its Spence copper mine in Chile by over 50 years, at a time when copper prices have reach their highest levels since late 2014.
The deal comes after a trip by the Guinean mines minister, Abdoulaye Magassouba, to China and follows other major Chinese investments in the resource-rich West African nation.
Lithium needed for rechargeable batteries used in high tech devices and electric cars might soon be extracted from calderas surrounding dormant supervolcanoes.