Junior diamond miner DiamonEx Ltd will raise up to $4 million through an initial public offering (IPO) as it tries to further develop its Martin's Drift deposit in Botswana. The company believes the site, abandoned by mining giant De Beers in December 2000, can be operated successfully after its former operator estimated it to contain 3.1 million carats of diamonds. De Beers' former exploration manager for Botswana and Tanzania, Don Duncan, has recently joined DiamonEx, which took over the prospecting licence to the site in July 2002. "DiamonEx believes that a number of issues were highlighted in the mine's final report which can be positively addressed by both improved methodology and a focused approach by a smaller company," DiamonEx said in a statement. DiamonEx executive chairman Greg King said the money raised would be used to conduct a feasibility study, with up to $15 million expected to be needed at a later date should full-scale production go ahead.