While suppliers are not required to comply with the 2017 Charter, the procurement targets for Holders indirectly require them to meet such targets to remain competitive.
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.