Cornerstone Capital Resources Inc. announced the following update on recent results from the ongoing comprehensive comminution and metallurgical test work program for the Alpala project at its Cascabel copper-gold porphyry joint venture in northern Ecuador. These include updates to the recovery parameters for copper, gold and silver and a comprehensive analysis of concentrate specifications from Locked Cycle test work completed and published in the comprehensive ALS Metallurgical Testing Cascabel Copper-Gold Project – Phase 1 Report. Cornerstone has a 22.8% direct and indirect interest in Cascabel comprised of a direct 15% interest in the project financed through to completion of a feasibility study and repayable out of Cornerstone’s share of project cash flow, plus an indirect interest comprised of 9.2% of the shares of joint venture partner and project operator SolGold Plc. SolGold is now actively engaged with concentrate market participants and expects to confirm alignment on the high quality and marketability of the Alpala concentrate in the prefeasibility study (PFS). Background on the Metallurgical Test Work and Design: Metallurgical test work on the Alpala project is being conducted by ALS Metallurgy Kamloops, British Columbia. The high precious metal bearing copper concentrates produced from the locked-cycle tests at Kamloops were then analyzed for trace elements by ALS Geochemistry in North Vancouver, BC. The test work program was carried out under the supervision and guidance of Dr. Gregory J. Harbort, General Manager Process and Metallurgy (SolGold Plc). SolGold Plc have specified a test program aligned with the resource size and quality to maximize capital payback early in the project. The ALS Report considered 5,500 kg of drill core from fifty-three variability samples representing different lithology, alteration styles and head grades, selected to provide a good spatial distribution within the mine plan. Further, the samples were composited into three master composites based on gold and copper head grade, to allow for optimization and locked cycle flotation tests and solid-liquid tests. Variability testing of the 53 samples has included extensive comminution testing² with SAG Mill Comminution (SMC) (profiling an orebody to predict its comminution circuit throughput as well as its rock mass characteristics and blasting properties), Bond Abrasion Index, and Bond Ball Mill Work Index testing. Bond rod mill work index tests were also conducted on selected samples, where sufficient material was available. Assessment of the elemental content of each Master Composite and variability sample was conducted via standard analytical techniques and multi-element ICP analyses. In addition, detailed scanning electron microscope (SEM) mineralogy was undertaken. Variability flotation test work included both kinetic roughing tests and open circuit cleaning tests. Davis Tube Recovery (DTR) tests were conducted on the rougher tailing to determine the amount of recoverable magnetite. Master Composite optimization tests focused on developing conditions to enhance recovery and concentrate grade, including size-by-assay analysis and diagnostic leach tests on the cleaner tailing stream. Locked cycle flotation tests were conducted under optimized conditions to produce expected plant recoveries, concentrate grades and mass balances to feed into the PFS. Concentrates produced were/are being assayed for an extended assay suite to confirm concentrate quality. The assays will also be used to evaluate the recovery of molybdenum and a valuable rhenium credit. Summary of Mineral Processing and Metallurgical Testing to Date The flotation locked cycle test is critical to simulating plant operation with regard to recirculating loads, water quality and reagents and has been the industry standard for developing circuit design for several decades. The locked cycle program has shown that the Alpala material responds rapidly to flotation, with low circulating loads and reagent addition. Further Planned Test Work: During 2020 a pilot plant operation is planned, to treat approximately 30 tonnes of core and coarse rejects. The material has been sourced and is currently being packaged. The pilot plant will allow for confirmation of the flowsheet at a larger design and provide copper sufficient concentrate to operate a molybdenum-rhenium recovery evaluation, conduct vendor thickening and filtration tests, measure rheological properties for concentrate pipeline design and measure transport moisture limits (TML) and supply samples for smelter evaluation. The large quantity of flotation tailing will allow testing of rougher recovery enhancements and magnetite recovery at a substantial scale, in addition to allowing for tailing deposition and environment tests. The production of significant pyrite concentrate allows for pilot testing of the cleaner recovery enhancement. The pilot is designed to be an effective blueprint for the first ten years of performance. At the same time material flow tests will be conducted allowing for ore chute and stockpile design. It is anticipated that several hundred kilograms will also undergo ore sorting evaluation trials. Summary of the Quality of Concentrates and Concentrate Specifications: The concentrate assay indicates a premium quality; high in copper and gold and low in deleterious elements. Copper measured between 29% and 31%, iron measured between 29% and 31%, and sulphur measured between 37% and 38%. Combined, these three elements account for 96% to 99% of the concentrate mass, indicating a very low level of dilution of these concentrates by non-sulphide minerals. None of the measured deleterious elements such as arsenic, bismuth, cadmium, chlorine, fluorine, mercury, selenium, tellurium, or uranium, were present at levels that typically are of concern; most measured at only trace levels. Similarly, Only trace amounts of magnesium and total organic carbon (TOC) were measured in the Alpala concentrates. This suggests little to no presence of typically hydrophobic non-sulphide gangue minerals. Very low levels of lead and zinc measured indicate little to no galena or sphalerite content in the concentrates. It is expected that there will be strong demand for the concentrate from South East Asian, North and South American, European and a limited number of Chinese smelters seeking to optimize their economics with a premium quality concentrate such as Alpala. Deleterious elements are low for a copper concentrate which will enhance the ability to market the Alpala concentrate, including the potential to achieve market leading payability. Alpala concentrate will allow smelters to consume greater quantities of complex material for which smelters receive a penalty payment, therefore optimising a smelter’s revenue without adversely affecting the smelter’s overall feed grade.