GR Silver Continues to Deliver Wide, High-grade Drill Results at Plomosas: 6.5 m at 1,458 g/t Ag Including 0.9 m at 3,118 g/t Ag in PLIP22-013

VANCOUVER, BC, May 24, 2022 /CNW/ - GR Silver Mining Ltd. ("GR Silver Mining" or the "Company") (TSXV: GRSL) (OTCQB: GRSLF) (FRANKFURT: GPE) – announces high-grade silver (Ag) results from underground infill drilling at the Plomosas Project in Sinaloa State, Mexico. The results continue to support the potential to increase Ag grades in the Plomosas Mine Area resource. The drilling targeted high grade Ag mineralization in the upper levels of the underground workings, in areas where unsampled intervals from historical drill holes within the 2021 resource block model were previously assigned zero values.

Highlights:

• Core drilling, in un-mined shallow areas (up to 160 m below surface) of the historical Plomosas Mine, continues to define attractive wide and high-grade Ag mineralization.
• Presence of high-grade results with predominance of Ag mineralization only in areas with potential to increase Ag grade in planned update of resource model, including:
• PLIP22-013: 6.5 m at 1,458 g/t Ag (1,485 g/t AgEq1), including
  0.9 m at 3,118 g/t Ag (3,266 g/t AgEq)
• PLIP22-012: 14.0 m at 146 g/t Ag, including
  0.4 m at 2,474 g/t Ag (2,542 g/t AgEq)
• PLIP22-011: 2.9 m at 190 g/t Ag, including
  0.4 m at 626 g/t Ag
• PLIP22-010: 8.3 m at 100 g/t Ag
• Ag mineralization on the hanging wall of the main polymetallic Plomosas Breccia, in the upper levels of the underground workings, supports the upside potential for Ag grades in the mineral resource update scheduled for Q1|23.
• The combination of systematic underground mapping, 3D modelling of different styles of mineralization and underground infill drilling at the historic Plomosas Mine has defined attractive, wide, high-grade gold-silver (Au-Ag) mineralized zones. These new zones will be incorporated into the upcoming mineral resource block model and estimation.
• Recent Ag drill results provide encouragement for the Company to continue drilling underground at the Plomosas Mine Area in 2022 (Figure 1) with the objective of significantly increasing the Ag grade in areas of the resource model.

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1 See Table 1 footnote

GR Silver Mining Chairman and CEO, Eric Zaunscherb commented, "The 2022 infill drill program at the Plomosas Mine has been carefully designed to address upside potential in the resource block model. It has been our thesis that historical sampling lacked detail in some unmined areas resulting in the adoption of zero grade in unsampled drill hole intervals in the current resource model. This is supported by the observation that current resource model grades in areas already mined are lower than suggested by historical production grades. Further, it is very encouraging to see such high-grade Ag results confirming the existence of new, high-grade Ag zones associated with previously ignored cross-cutting structures. It is highly satisfying to see further proof of concept on both themes, with the potential for a commensurate re-rating."

The underground infill drilling program at the Plomosas Mine Area commenced in March 2022 and is ongoing. The drill holes are predominantly short holes planned to target zones where recent geological mapping identified opportunities to improve the 2021 NI 43-101 mineral resource block model Ag grade, utilizing areas of the underground development that provide good access.

The underground drilling program is designed to, not only address the shortcomings in the 2021 resource model, but also delineate high-grade Ag-Au mineralized zones located between level 775 RL and 1025 RL (see Figure 2). The underground infill drilling program has a surgical approach using drill rigs with the capacity to drill NQ and BQ diameter holes in selective and tight underground sites, aiming to drill a total of 4,350 m by Q4|22.

The existing underground infrastructure within the Plomosas Mine, which includes a total of 7.4 km of ramps and galleries, provides flexibility and optimization of the program scheduling, avoiding the need for additional new underground development or long drill holes from surface.

A total of 13 holes have been completed underground to date in 2022. Major highlights from the initial 13 holes are summarized in Table 1. These intervals confirm consistent high-grade Ag mineralization and have also delineated new mineralized zones in areas not previously drilled. Upon completion of the underground infill drill program in Q4|22, the Company anticipates commencing a resource upgrade for the Plomosas Mine Area.

The drill holes PLIP22-10, PLIP22-11, PLIP22-12 and PLIP22-13 have successfully discovered wide, high-grade Ag mineralization hosted by hydrothermal breccias (Figure 3) located in the hanging wall of the previously mined polymetallic (Ag-Au-Pb-Zn) hydrothermal Plomosas Breccia.

This recently mapped zone is located in a section of the Plomosas Mine where the Company initially defined prospective NE-trending faults with potential to host additional Ag-Au only mineralization. These zones were not previously the subject of significant exploration due to the focus on base metals in the historical plant flowsheet. Historical production, and hence exploration, targeted Pb-Zn rich mineralization at the Plomosas Mine.

The drill holes from PLIP22-01 to PLIP22-09 (Table 1) consistently intersected high grade Ag-Au mineralization hosted in a polymetallic (Pb-Zn) hydrothermal breccia. All nine holes indicate the presence of multiple hydrothermal zones with Ag results generally >200 g/t Ag and individual Au grades up to 4.5 g/t Au in locations drilled along strike on the 1025 RL level.

Table 1: Plomosas Mine Area - Drill Results

Table 2: Plomosas Mine Area - Surface Infill Drill Hole Details

The scientific and technical data contained in this News Release related to the exploration program were reviewed and/or prepared under the supervision of Marcio Fonseca, P. Geo. He has approved the disclosure herein.

GR Silver Mining is a Canadian-based, Mexico-focused junior mineral exploration company engaged in cost-effective silver-gold resource expansion on its 100%-owned assets, located on the eastern edge of the Rosario Mining District, in the southeast of Sinaloa State, Mexico. GR Silver Mining controls 100% of two past producer precious metal underground and open pit mines, within the expanded Plomosas Project, which includes the integrated San Marcial Area and La Trinidad acquisition. In conjunction with a portfolio of early to advanced stage exploration targets, the Company holds 734 km2 of concessions containing several structural corridors totaling over 75 km in strike length.

GR Silver Mining Ltd.
Eric Zaunscherb
Chairman & CEO

This press release contains "forward-looking statements" within the meaning of applicable Canadian securities legislation and information that are based on the beliefs of management and reflect the Company's current expectations. When used in this press release, the words "estimate", "project", "belief", "anticipate", "intend", "expect", "plan", "predict", "may" or "should" and the negative of these words or such variations thereon or comparable terminology are intended to identify forward-looking statements and information. Such statements and information reflect the current view of the Company. Risks and uncertainties may cause actual results to differ materially from those contemplated in those forward-looking statements and information. By their nature, forward-looking statements involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements, or other future events, to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this press release.

SOURCE GR Silver Mining Ltd.

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