Stellar Diamonds said it made a 'number of positive advancements' in the last six months of 2013. In particular, Chief Executive Karl Smithson was "delighted" by the progress made at the company's flagship high grade Tongo project, which he said shows "robust economics justifying the Board's decision to advance the project to the feasibility study phase".The Tongo Kimberlite Dyke Project in Sierra Leone project was commissioned to undertake an economic scoping study on Tongo Dyke-1, which was delivered on budget and on schedule in July 2013. Sample processing results to date have so far yielded 551.6 carats for an average grade of 126.3 carats per hundred tonnes (cpht). The diamonds have been classified with an average of 77.63% gem quality with several stones greater than 1 carat in size, including a 6.70 carat diamond discovered in the most recent sample.The company anticipates that these high grades will increase as further diamonds are recovered following re-processing. At the Baoulé project in Guinea, a joint venture was signed in December 2013 with Société Tassiliman.Development has commenced post period with a target to define a 3m carat resource by the end of 2014."Having already delivered on several significant milestones during 2013, we look forward to the year ahead as we aim to further unlock the potential and advance towards our goal of becoming a diamond producer in West Africa," Smithson concluded. Shares rose 1.22% to 2.08p at 14:20 on Thursday.RD