Stellar Diamonds PLC (LON:STEL) reported encouraging initial diamond grades from bulk sampling at its 100 percent owned Tongo kimberlite project in eastern Sierra Leone.
The company has recovered an in-situ kimberlite grade of 130 carats per hundred tons (cpht) from the first 69 tons processed during the commissioning of the Dense Media Separation (DMS) plant.
Of the 59.25 carats so far recovered from the bulk sample 53.46 carats, 90 percent, are classified as being of gem quality.
Chief executive Karl Smithson said: "The initial processing results from the Tongo kimberlite bulk sampling programme are highly encouraging. The predominance of gem quality stones in the diamond population so far observed can only bode well for the future diamond value of this kimberlite body.”
"We are accelerating the processing rate in order that a representative parcel of diamonds can be exported to Antwerp for valuation purposes. The objective is to collect a 1,000 carat to 2,000 carat bulk sample, the results of which will determine the next phase of evaluation and development work.”
A total of 1,000 tons of sample has been collected to date from a 70 metre long section of the 2.5 kilometre long kimberlite Dyke 1. The first 1,000 tons have been batched into 5 samples to date.
Construction and commissioning of the Tongo processing plant has now been completed, and thus the rate of processing is expected to increase going forward.
While no conclusions can yet be drawn as to the diamond value of the Dyke 1 kimberlite, due to the small parcel of stones obtained so far, a 130 carat parcel of stones previously recovered from Dyke 1 by Stellar was recently re-valued for the company at US$169 per carat. The same parcel was valued at US$144 per carat in May 2010, with the relative price increase reflecting the improvement in the diamond market in the second half of 2010.
"Stellar's strategy is to grow significantly by developing a series of high-grade kimberlites into economic diamond mines. In the past six months Stellar has delivered excellent drilling and microdiamond results from the Droujba kimberlite pipe in Guinea and now we are able to announce initial high-grades from the Tongo kimberlite dyke. We will continue the development of these key assets over the coming months," CEO Smithson said.
Stellar has a portfolio of projects in West Africa. It also owns full rights over four high-grade kimberlites that are the focus of exploration and development.
In Sierra Leone at the Tongo project a bulk sampling programme is ongoing on one key kimberlite to assess the diamond grade and value. At the Kono underground trial mine, bulk sampling has produced 4,200 carats as part of an economic evaluation exercise. In Guinea drilling is continuing on the diamondiferous Droujba kimberlite pipe and bulk sampling is being planned on the high grade Bouro kimberlite dyke, which is adjacent to Stellar's Mandala alluvial diamond mine.