Lesotho is a country well known for its diamonds and is home to some of the biggest diamond finds in the world. However, since the discovery of diamonds at Letseng in 1967, the contribution of diamond mining to the economy of Lesotho has been unpredictable. In the past diamonds were not mined consistently because most of the initial feasibility studies conducted at the exploration stage showed that diamond mining in Lesotho could not be sustained and commercialised. This initial conclusion was, however, not supported by individual miners who continued to mine despite the survey findings. Some small companies and individual diggers actually found gems and diamond pipes that could be considered commercially sustainable. These findings justified the re-commissioning of feasibility studies to confirm the discovery of the pipes by diggers and some marginal mines.