Properties

Highlights

• Target: Copper/Gold porphyry mineralization
• JV between Cornerstone (15% financed through BFS and repayable out of project revenues) and SolGold (85%) - subject to SolGold funding 100% through BFS
• Cornerstone also owns 8.2% of SolGold, or 22% interest (direct & indirect) in Cascabel
• Alpala deposit updated Mineral Resource Estimate #3 (MRE#3) (see Cornerstone news release 20-09 dated April 7, 2020) reports:
• 2,663 Mt @ 0.53% copper equivalent (CuEq) (containing 9.9 Mt Cu, 21.7 Moz Au, and 92.2 Moz Ag) in the Measured plus Indicated categories, comprising:
• 1,192 Mt at 0.72% CuEq in the Measured category (containing 5.7 Mt Cu, 15 Moz Au, and 52.4 Moz Ag); and
• 1,470 Mt at 0.37 CuEq in the Indicated category (containing 4.2 Mt Cu, 6.6 Moz Au, and 39.8 Moz Ag).
• High-grade core of 442 Mt at 1.40% CuEq in the Measured and Indicated categories, supporting early cash flows and accelerated pay back of initial capital, comprising:
• 359 Mt at 1.47% CuEq in the Measured category (containing 3.2 Mt Cu and 10.9 Moz Au); and
• 84 Mt at 1.06% CuEq in the Indicated category (containing 0.6 Mt Cu and 1.4 Moz Au).
• Additional Inferred Resource of 544 Mt @ 0.31% CuEq for 1.3 Mt Cu, 1.9 Moz Au and 10.6 Moz Ag.
• MRE#3 update has added 1.6 Mt copper, 2.5 Moz gold and 92.2 Moz silver to Measured and Indicated Mineral Resources providing a solid resource basis for the forthcoming Preliminary Feasibility Study ("PFS").



Mineral Resource:  Measured and Indicated Category
Cut-off grade	Mt	Grade				Contained metal
		CuEq (%)	Cu (%)	Au (g/t)	Ag (ppm)	CuEq (Mt)	Cu (Mt)	Au (Moz)	Ag (Moz)
0.21%	2,663	0.53	0.37	0.25	1.08	14.0	9.9	21.7	92.2
High Grade Core:  Measured and Indicated Category
Cut-off grade	Mt	Grade				Contained metal
		CuEq (%)	Cu (%)	Au (g/t)	Ag (ppm)	CuEq (Mt)	Cu (Mt)	Au (Moz)	Ag (Moz)
0.80%	442	1.40	0.87	0.86	2.34	6.2	3.8	12.3	33.3



• MRE#3 was prepared by Cecilia Artica SME Registered Member, Principal Geology Consultant of Mining Plus (see Table 1, above), who is designated as the "Qualified Person" as defined by Canada's National Instrument 43-101.
• See also:
• News Release 20-09 - Alpala Mineral Resource Estimate # 3 delivers significant tonnage conversion to Measured Category
• News Release 19-12 - Cornerstone Announces Positive PEA Results for Cascabel Project
• MRE#2 Technical Report (filed on Sedar January 3, 2019) - http://www.cornerstoneresources.com/i/pdf/AlpalaMRE_1218.pdf

See home page for link to technical report filed at www.sedar.com for PEA. A link to the technical report for the April 7, 2020 MRE#3 will be posted as soon as that report has been filed on SEDAR.

Maps

Regional Map	Infrastructure Map	Development Proposal
Cascabel Targets	Cascabel Drilling	Cascabel CSD-16-016 Core Images
Cascabel CSD-16-017 Core Images	Cascabel CSD-16-15R2 Core Images	Cascabel CSD-16-016 Core Images
Cascabel CSD-16-016 Core Images	Cascabel CSD-16-017 Core Images	Cascabel Drill Intercept Table




Photos

General Topography	Gold Panning	Cross-cutting quartz-chalcopyrite-pyrite veinlets	Malachite along fractures


^{* Mr. Martin Pittuck, MSc, CEng, MIMMM, is responsible for the Mineral Resource Estimate and is an "independent qualified person" as such term is defined in NI 43-101.}