Firestone has now completed its third diamond tender in Gaborone, Botswana, and a further three tenders are planned in 2011. The company plans to hold a diamond sale approximately every two months in 2012.

Firestone Diamonds PLC (LON:FDI) has completed its second sale this year in Gaborone, Botswana, and achieved a 42 percent rise in value for its diamonds compared to the previous tender in April.

In all, it sold 14,248 carats for gross proceeds of approximately US$2 million. Demand from local and international buyers remained extremely strong, the group said, with a total of 31 companies attending the tender.

It sold 12,212 carats from the main pipe and the satellite pipe at the Liqhobong mine in Lesotho at an average price of US$123/carat, an increase of 12 percent from April. Main pipe diamonds sold for US$149/carat, an increase of 15 percent from April for run of mine production and 52 percent from the December 2010 tender.

Firestone said prices for small diamonds and cape yellows and browns continue to be very strong, and it expects to achieve higher prices for main pipe production as mining moves to the higher grade and higher value K5 and K6 units later this year.

The grade of material processed from Liqhobong’s main pipe continues to be significantly higher than the published resource grade, with the production grade of 34 carat per hundred tonnes (cpht) from the K2 unit being 30 percent higher than the resource grade of 26 cpht. Firestone expects these grades to be maintained, which would give the main pipe a value of over US$50/tonne.

The group also sold 2,036 carats from the BK11 mine in Botswana at an average US$235/carat, 16 percent higher than in the April tender and up 33 percent from December 2010.

Chief executive Tim Wilkes said: "The results achieved from this tender reflects the continued strong demand for rough diamonds and the quality of production from Liqhobong and BK11.

“With diamond prices expected to remain strong and higher than expected grades being achieved from the main pipe, the value of Liqhobong continues to increase significantly. The demand for the higher quality production from BK11 has also yielded very good results."

Firestone has now completed its third diamond tender in Gaborone and a further three tenders are planned in 2011.

Subject to market conditions and the size of production available for sale, the company plans to hold a diamond sale approximately every two months in 2012.

With significantly higher production expected from Liqhobong in 2012 following the completion of the Plant 1 expansion, which will result in capacity being tripled to 1.3 million tonnes per annum, the 2012 tenders are expected to be significantly larger than those held in 2011.