JOHANNESBURG (miningweekly.com) – An inferred mineral resource of 7.1-million cubic metres of Rooikoppie gravel at a grade of 0.9 ct per 100 m (cphm3) with an average value of $2 900/ct has been estimated at dual-listed Rockwell Diamonds’ Remhoogte operation, after historical, geological and field mapping data was re-evaluated.
This estimate was also concluded from a survey of areas mined since the start of operations on the property and the available production and sales results. The largest stone recovered from Remhoogte to date was 178 ct.
The company said on Monday that it would continue its exploration programme in the region and planned to spend R4-million in the year ahead on field mapping and geological delineation.
“[The] estimation of an inferred resource at Remhoogte has the potential to add 63 500 ct to our diamond inventory. This further entrenches Rockwell’s positioning in the [Middle Orange River (MOR)] alluvial diamond fields,” Rockwell CEO and president James Campbell said.
“In the short term, our intended acquisition of the Remhoogte/Holsloot project is expected to lift our monthly volume beyond our 500 000 m3 target,” he added.
Further, as part of its ongoing evaluation of the Bondeo acquisition properties, the company identified an exploration target with potential for a further three-million to four-million cubic metres of fluvial-alluvial gravels, with target grades of about 0.4 cphm3 to 1.5 cphm3 and anticipated diamond values ranging from $2 500/ct to $4 000/ct.
Limited sampling of the fluvial-alluvial gravel has recovered 446 ct, with the largest diamond recovered being a 27 ct stone.
Meanwhile, as part of its ongoing exploration of the MOR diamond potential, Rockwell entered into an exploration agreement with the rights holder of the 2 300 ha Lanyonvale property, considered to be transgressed by paleo river channels with significant potential to add to the company’s resources and mining flexibility.
The company could now determine the potential of the property, which was contiguous to the western boundary of Wouterspan and the northern boundary of Niewejaarskraal.
“The Lanyonvale exploration agreement, together with the recently granted mining and prospecting rights in the MOR, will provide additional greenfield opportunities to support our longer-term organic growth objectives,” Campbell added.
Subject to positive results, the company would include the property in its mining plans.
“With the additional MOR exploration and development projects, there is potential for us to be able to further grow our production base and improve the company’s profitability post the Bondeo acquisition.
“We have launched a formal exploration programme, underpinned by our in-depth knowledge of the regional geology, to ensure that we deliver these new opportunities as projects,” Campbell noted.
Rockwell recovered a high-value 121 ct yellow octagonal rough diamond at its flagship operation Saxendrift, also in the MOR.
Since September, the company has recovered ten diamonds bigger than 100 ct in the MOR.