Collective Mining Expands the New Porphyry Discovery at San Antonio by Cutting 172.40 Metres at 1.40 g/t Au, 0.16% Cu, 17 g/t Ag and 68 ppm Mo with the Hole Bottoming in Strong Mineralization

Latest drill results at San Antonio into the Pound target have expanded the footprint of the recently discovered porphyry system and intersected multiple mineralized zones:

• Hole SAC-18, located two hundred and fifty metres south of previously announced discovery hole SAC-11, was drilled vertically into a mineralized porphyry system and intersected:
  • 172.40 metres @ 1.88 g/t gold equivalent (1.40 g/t Au, 0.16% Cu, 17 g/t Ag, 68 ppm Mo) including:
    • 28.50 metres @ 3.32 g/t AuEq (2.05 g/t Au, 0.20% Cu, 62 g/t Ag, 12 ppm Mo) and
    • 60.75 metres @ 2.27 g/t AuEq (2.05 g/t Au, 0.17% Cu, 4 g/t Ag, 98 ppm Mo)
  • The hole was terminated prematurely while in strong mineralization due to the limitation of the rig with the final 1.60 metres averaging 2.03 g/t AuEq
• Hole SAC-15 was drilled to the south from the same pad as SAC-18 at a flatter angle and also intersected the same mineralized system returning:
  • 154.20 metres @ 1.22 g/t gold equivalent (1.12 g/t Au, 0.03% Cu, 11 g/t Ag) including:
    • 58.00 metres @ 2.15 g/t AuEq (1.95 g/t Au, 0.03% Cu, 21 g/t Ag)
    • 16.05 metres @ 2.17 g/t AuEq (2.03 g/t Au, 0.08% Cu, 12 g/t Ag)
  • SAC-15 also bottomed in strong mineralization due to the depth capacity limit of the rig with the final 9.90 meters averaging 3.18 g/t AuEq (2.99 g/t Au, 0.11% Cu, 17 g/t Ag).
• Three porphyry related mineralized phases have now been identified at the Pound target as follows:
  • Phase 1 is a large, three by three-kilometre area covering the entirety of the San Antonio project displaying a phyllic altered, porphyry halo zone, which hosts low grade gold (0.2 g/t Au-0.5 g/t Au), extends from surface to a minimum of 700 metres depth and is open in all directions.
  • Phase 2 is a late-stage, gold and silver rich sheeted veinlet system (CBM Veins) beginning at surface but with more robust grades starting from 300 metres below surface (see Table 3). Phase 2 mineralization is found close to or in contact with the Phase 3 porphyry system.
  • Phase 3 is a gold-copper-silver-molybdenum porphyry system with potassic alteration (secondary biotite). This system commences at approximately 400 metres below surface and displays an unusually high gold to copper ratio of up to 4:1 in grade. Both Phase 2 and Phase 3 mineralized zones are found within the large Phase 1 mineralized porphyry halo (See Table 2).
• Drill holes SAC-11 (see press release dated May 5, 2025), SAC-15 and SAC-18 have tested approximately 450 metres of north-to-south strike length with the system remaining open in all directions. Due to rig limitations, holes SAC-15, SAC-18 and SAC-20 (assay results pending) were stopped prematurely while still in strong mineralization. A higher capacity rig is now drilling hole SAC-21 and is progressing at a significantly improved rate.
• Magnetic Vector Inversion (“MVI”) modelling of airborne geophysical data is proving to be quite useful at identifying Phase 2 and Phase 3 porphyry mineralization (see Figure 2) and as a result drill hole SAC-21 is currently being directed into an MVI high.

TORONTO, Aug. 25, 2025 /PRNewswire/ – Collective Mining Ltd. (NYSE: CNL) (TSX:CNL) (“Collective” or the “Company”) is pleased to announce that drilling assay results from the San Antonio Project’s Pound target (“Pound”) have confirmed that the Company has discovered a high-grade porphyry system over a minimum strike length of 450 metres (open), which locates within a gold mineralized halo envelope measuring 3 kilometres x 3 kilometres and is open in all directions.  The San Antonio Project is located between 2 kilometres and 5 kilometres to the east-northeast from the Company’s flagship Guayabales Project within the Caldas Department in Colombia.