Firestone Diamonds expects double-digit growth in the next five years, Firestone's CEO Philip Kenny told Interactive Investor this week.

Kenny noted that the diamond trade was driven "purely by supply and demand" and that currently, demand for diamonds was outpacing the supply of stones.

Last year, Firestone announced that it intended to acquire Kopane Diamond Developments, which would give the company the Liqhobong diamond mine in Lesotho – the world's third-largest mine in terms of carat resources.

The acquisition of Liqhobong, Kenny said, brings the group closer to its goal of producing a million carats of rough diamonds annually by 2014.