Botswana Diamonds (LSE: BOD) has begun mining at Marsfontein in South Africa, as a proof-of-concept trial project that it expects will help improve operations at its larger Thorny River project. The company, headquartered in Ireland with 12 other subsidiaries, experienced “teething issues,” including plant delivery delays and adverse weather, said it’s now on track to start production at Thorny River in the second half of this year. Botswana Diamonds is working on bringing the two projects — Marsfontein and Thorny River — into production this year. Marsfontein is currently processing 500 tonnes a day of dumps and gravels, the miner said. Although diamonds are being produced, the company said it did not yet have an accurate representation of the average grade and quality. Drilling on the Thorny River kimberlite dyke system over the past two years helped identified two areas of interest for commercial mining. Following a preliminary assessment of Thorny River’s kimberlite potential, the company estimated last year that the asset hosted about 2 million tonnes of kimberlitic material, up from the 1.2 million previously determined. Botswana Diamonds said on Wednesday it expects the grade of the two high-grade deposits to be between 46 carats per hundred tonnes (cpht) and 74 cpht of good-quality diamonds. “We plan to mine these hotspots using the same operational approach as at Marsfontein, for a 15% production royalty agreement,” chairperson John Teeling said in the statement. “However, most early-stage investors in the company continue to support new funding efforts.” The executive noted that Marsfontein and Thorny River will deliver cash with no further capital expenditure.