Star Diamond Corp. [DIAM-TSX; SHGDF-OTC] announced that a total of 2,822 diamonds weighing 130.26 carats have to date been recovered from the third bulk sample trench (19FALCT003) excavated on the Star Kimberlite at the Star-Orion South Diamond Project, part of the 100%-owned Fort à la Corne Diamond Project 60 km east of Prince Albert, central Saskatchewan.
These initial results are from the third of 10 bulk sample trenches that were excavated by Rio Tinto Exploration Canada Inc. in 2019. The preliminary results from the first two bulk sample trenches were previously disclosed. The average diamond grades from the first three trenches are similar to historical diamond grade results detected from the underground bulk sampling and large diameter drilling completed on the Star Kimberlite between 2004 and 2009.
These results are also similar to the overall weighted average grade (14 cpht) reported in Star Diamond’s Preliminary Economic Assessment of the Star and Orion South kimberlites. The three largest diamonds recovered to date from 19FALCT003 are 6.28, 1.95 and 1.49 carats, respectively, and were all recovered from Early Joli Fou (EJF) kimberlite. The 6.28-carat stone is a clivage fragment of a larger stone that was probably fragmented during the original kimberlite eruption as all surfaces of this stone have been resorbed by reaction with the kimberlite magma. The EJF is the dominant kimberlite unit within the project in terms of ore volume and diamond grade.
As disclosed August 4, 2020, there are indications that recent diamond breakage has occurred in the diamond parcels recovered thus far from RTEC’s trench cutter bulk sampling program, suggesting that the extraction and/or processing systems being used by RTEC may be resulting in diamond breakage. Comprehensive diamond breakage studies are required to assess the nature, extent and potential causes of the diamond breakage, and the possibility that larger diamonds would have been recovered absent such breakage.
Senior Vice President Exploration and Development, George Read, states: “The initial diamond results from 19FALCT004, 19FALCT001 and 19FALCT003 continue to show grades similar to the previous underground bulk sampling and LDD performed by Star Diamond on the Star Kimberlite. Individual EJF kimberlite samples recovered in the first three trenches exhibit a range of grades (9.81 to 21.22 cpht for 19FALCT004, 4.88 to 23.34 cpht for 19FALCT001 and 8.71 to 23.39 cpht for 19FALCT003), which are as expected for the EJF kimberlite.”
To date, kimberlite material from six trenches (19FALCT001, 19FALCT004, 19FALCT003, 19FALCT010, 19FALCT008 and 19FALCT009) has been processed by RTEC through the on-site Bulk Sample Plant with concentrates forwarded to the Saskatchewan Research Council (SRC) for diamond recovery and reporting.
Currently, only the initial diamond results for the first three trenches have been reported by the SRC.