Mr. Ioannis Tsitos reports

GOLDSOURCE ANNOUNCES HIGH METALLURGICAL RECOVERIES FOR EAGLE MOUNTAIN

Goldsource Mines Inc. has released high metallurgical recoveries and a positive grinding cost-benefit analysis at its 100-per-cent-owned Eagle Mountain gold project in Guyana, South America. The metallurgical results show an average gold recovery of 96.7 per cent, of which 24.4 per cent of the recovery was from gravity tests and the remaining recovery was through cyanidation. The metallurgical testwork was conducted by SGS Canada Inc. at Lakefield, Ont., under the supervision of Tetra Tech Inc. The company has retained the services of Tetra Tech, an independent Vancouver-based company, to complete a prefeasibility study for a potential large-scale open-pit, gravity-cyanidation operation at Eagle Mountain.

Highlights of metallurgical study results for PFS:

• Average gold recovery of an estimated 96.7 per cent, including an average recovery of 24.4 per cent from the gravity tests with the remaining recovered through cyanidation;
• Conceptual grind size of an estimated 200 microns (P80) through a standard gravity CIP (carbon-in-pulp) plant;
• Approximately a minimum of 45 per cent of mineralized saprolite is minus 200 microns and could bypass the grinding circuit with potential positive benefits in capital and operating costs;
• Low abrasiveness and standard work index in the saprolite mineralization;
• Leach residency times and reagents consumption within comparative standard industry levels;
• Positive cyanide detoxification results.

Yannis Tsitos, president, commented: "We are very pleased with the metallurgical results, which are consistent with the preliminary gold recoveries announced on May 17, 2018. The overall gravity-cyanidation gold recovery remains at high levels (over 95 per cent) even at coarser saprolite feeds in excess of 500 microns. Results indicate that a minimum of 45 per cent of the total mineralized saprolite could bypass the grind circuit. Our efforts will continue at Eagle Mountain with focus on saprolite resources expansion, resource estimation and the conclusion of the PFS study."

Twenty-two saprolite samples representing the different mineralized zones of the Eagle Mountain deposits were collected (trench and core) with additional samples representing the existing pilot gravity plant tailings and the plus-two-millimetre stockpile from the same operation. The bulk sample, totalling approximately 500 kilograms, was shipped to SGS Lakefield in the first quarter of 2018 for testing.

The test program consisted of grindability testing, sample characterization (assaying, sizing, mineralogy and gold deportment), followed by gravity separation and cyanidation. The received samples were grouped into seven composites designated as VC1 through VC7 for the purposes of the test program. The master composite is a blend of the composite samples (VC1 to VC4 and VC7). The composite sample VC5 is representative of the existing pilot gravity plant tailings from the 2016 operation. The composite sample VC6 is representative of the plus two mm stockpile from the same pilot plant operation.

The results of the detailed metallurgical testwork are summarized as follows and in the attached table.

• The bond ball mill work index is 16.3 kilowatt-hours per tonne for the coarse fractions of the master composite (with no fines) and 8.1 kWh/t for the overall sample (including fines).
• The bond abrasion index is 0.004, and indicates low abrasiveness in the mineralization.
• The gold grade for the master composite sample was 0.98 g/t. The sulphur (as pyrite) content is less than 0.05 per cent. No deleterious elements were noted in assays results.
• For the master composite sample, approximately 50 per cent of the gold occurs within the finer fraction of minus 25 micron.
• The gravity concentration tests, excluding pilot plant tails, resulted in a gold recovery between 18.9 to 29.5 per cent averaging 24.4 per cent.
• Average cyanide leach test results from gravity tailings showed an average gold recovery of 96.7 per cent, which is in line with the results from the master composite sample.
• Test results show that the optimal grind size of an estimated 200 microns (P80) is required for the gravity followed by leaching, the applied standard condition for cyanide concentration was 0.5 gram per litre.
• The cyanide detoxification results indicated that the CNWAD, present in the CIP barren pulp, could be destroyed to levels below the typical effluent discharge requirement of one mg/L.

                              SUMMARY OF GRAVITY AND CYANIDE LEACH RESULTS

Sample No.       Sample description    Head gold       Feed size            Gravity gold     Gravity + CN** gold
                                      grade (gpt)    P80 (microm) extraction/recovery (%) extraction/recovery (%)

VC1                      Zion 01-07         0.90             173                    27.6                    97.6
VC2                      Zion 08-10         1.29             175                    25.4                    96.0
VC3                    Kilroy 01-06         1.13             132                    18.9                    97.4
VC4                    Kilroy 07-08         0.39             162                    29.5                    94.8
VC5       Pilot Gravity Plant Tails         0.77             761*                    N/A                    87.4
VC6                      Stock +2mm         1.99             195                    13.7                    93.6
VC7            Saprolite Drill Core         1.17             179                    20.7                    97.7
Average                VC1 to 4 & 7         0.98             164                    24.4                    96.7
                    
Notes:
* VC5 sample (pilot gravity plant tailings) without prior grinding or additional gravity separation; already 
passed through the Falcon gravity concentrators at the pilot plant.
** 48-hour leach residency times.

                  SUMMARY OF GRAVITY AND CYANIDE LEACH RESULTS FROM COARSER GRINDING

Sample No.       Sample description    Head gold       Feed size            Gravity gold     Gravity + CN** gold
                                      grade (gpt)    P80 (microm) extraction/recovery (%) extraction/recovery (%)

CN5                Master Composite         0.98             563                    26.0                    97.6
CN6                                                          186                                            97.0
CN7                                                          124                                            97.3

Notes:
** 48-hour leach residency times.

The recommended proposed design rate for mineralized saprolite volume to bypass the grinding circuit for the PFS is 45 per cent. No additional metallurgical testwork is recommended at this stage. However, further metallurgical testwork may be justified depending on the success of expansion drilling on newly defined targets.

Based on the detailed metallurgical results, the general flowsheet for PFS conceptually suggests an open-pit mining operation followed by a standard gravity-grind-leach (CIP) processing facility at a throughput rate of 4,000 to 5,000 t/d.

The qualified persons under National Instrument 43-101 -- Standards of Disclosure for Mineral Projects for this news release are N. Eric Fier, CPG, PEng, chief operating officer and executive chairman for Goldsource, and Hassan Ghaffari, MASc, PEng, director, metallurgy mining and minerals, Tetra Tech, who have reviewed and approved its contents.

About Goldsource Mines Inc.

Goldsource Mines is a Canadian resource company working aggressively to develop its advanced-stage, 100-per-cent-owned Eagle Mountain saprolite and hard-rock gold project in Guyana, South America. From 2016 to 2017, through a gravity pilot plant initiative, the company completed testing on gravity-only gold production and both dry and wet mining open-pit techniques. Goldsource is now focused on delivering feasibility studies to achieve large-scale gold production at Eagle Mountain.

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