Espiritu trench at Bramaderos Au-Cu Project (Ecuador) exposes gold-silver polymetallic veins intersecting 4m at 415g/t silver, 0.9g/t gold, 6.9% zinc and 6.0% lead - Seite 2

Trench ES-01	Interval (m)	Gold (g/t)	Silver (g/t)	Lead (%)	Zinc (%)
	21	0.3	82.4	1.2	1.4
including	4	0.9	414.8	6.0	6.9
including	1	1.4	1001.0	16.9	5.7

Targeting of similar mineralized systems within the Bramaderos concession has been on-going during the Covid-19 shut down period and has resulted in the generation of multiple targets (Figure 1). These will be explored initially with more detailed soil sampling. This work has commenced at target E-1 (Figure 1).

Polymetallic Gold-Silver deposits:

Polymetallic gold-silver deposits are a class of epithermal to mesothermal vein deposits and replacement bodies which typically occur around the margins of porphyry gold-copper deposits. They are structurally controlled, display a range of gold-silver-lead-zinc-copper ratios and can occur over many kilometres around large porphyry systems. They appear to be relatively more common in South America and can develop into significant orebodies in their own right, such as Fresnillo in Mexico (83mt at 0.58g/t gold and 395g/t silver)(ref - J. Cunliffe, in Terry Leach Symposium 2008).

About Bramaderos

Measuring 4,948 hectares, the Bramaderos project is located approximately 130km from the Loja provincial capital in southern Ecuador. The project is easily accessible via the Pan American Highway that crosses the property.

The Bramaderos concession is owned by La Plata Minerales S.A. (“PLAMIN”), which in turn is owned 87.5% by Sunstone (the project operator) and 12.5% by Cornerstone. Cornerstone’s 12.5% interest is carried by Sunstone through to the start of commercial production and repayable at Libor plus 2% out of 90% of Cornerstone’s share of earnings or dividends from the Bramaderos project (see news release 20-01 dated January 7, 2020).

More information about the property can be found at www.cornerstoneresources.com.

Qualified Person:

Yvan Crepeau, MBA, P.Geo., Cornerstone’s Vice President, Exploration and a qualified person in accordance with National Instrument 43-101, is responsible for supervising the exploration program at the Bramaderos project for Cornerstone and has reviewed and approved the information contained in this news release.