(ShareCast News) - Natural resources investment company Polo Resources announced on Thursday that Blackham Resources Limited has reported the successful achievement of another milestone towards gold production, with the commencement of open pit mining operations and underground development work at the company's Matilda Gold Project.The AIM-traded firm said contractors have commenced mining at the Matilda M10 open pit and underground development work at the high grade Golden Age orebody.Wet commissioning of the Wiluna processing plant is on track to begin in August 2016, the board added."The commencement of mining represents another significant milestone in Blackham's transition from gold explorer to gold producer at a time of record Australian gold prices and gold production remains on track for the September 2016 quarter," Polo's board said in a statement."The project has an initial mine life of eight years that has the potential to grow rapidly."The board said Blackham's 780 sq km tenement area is highly prospective, and it was recent;y announcd that the exploration team had already managed to increase the project's ore reserves to seven million tonnes at 2.5g/t for 560,000 ounces - up 17% since the project's definitive feasibility study.It also managed to increase the mining inventory to 9.3 million tonnes at 2.9g/t for 873,000 ounces - up 14% since the DFS - and increase the project's resource to 48 million tonnes at 3.3g/t for 5.1 million ounces, all located within a 20km radius of Blackham's Wiluna gold plant.Polo's board confirmed its shareholding in Blackham is approximately 8.11%.