(IDEX Online) - Newfield Resources has secured $50m in provisional finance to bring its Tongo Diamond Mine, in Sierra Leone, to commercial production.The Australian miner says the deposit has an initial eight-year life with peak annual diamond production of 260,000 carats forecast in Year 5.Newfield said yesterday (10 July) that its subsidiary Sierra Diamonds Limited (SDL) had signed a conditional and non-binding terms sheet with the Africa Finance Corporation (AFC).Karl Smithson, executive director at Newfield, said: "Through its own funding, Newfield has substantially advanced the Tongo Mine from exploration to development and into first production. "We believe that the right financing partnership will enable the Tongo Mine to move to full-scale production and create many positive benefits for all stakeholders, including the local communities, the Government of Sierra Leone and the shareholders of Newfield."It says 80 per cent of its run of mine product is gem quality, compared to a global average of only 20 per cent. Two adjacent mining licences cover over 134 square km and host 11 known kimberlites.Five of those kimberlites have been incorporated into the current JORC-compliant 8.3 million carat diamond resource estimate.The first diamond sales of 5,200 carats from Tongo achieved an average sales price of $262 per carat last May. A second diamond sale of over 7,000 carats will take place later this month.Newfield took over Tongo in March 2018 when it acquired London-based Stellar Diamonds for $23.6m. Before that the mine was owned by Israeli Beny Steinmetz, through Koidu Holdings, in which he held a controlling stake.Pic courtesy Newfield shows rough diamonds from its Tongo mine.