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GR Silver Mining Reports High-Grade Silver Intercepts in San Marcial Area Step-Out Drilling. SMS25-12 Returns 5.0 m at 232 g/t Ag, from 332.6m downhole, including 0.9 m at 956 g/t Ag

Drill Results

GR Silver Mining Reports High-Grade Silver

Intercepts in San Marcial Area Step-Out

Drilling. SMS25-12 Returns 5.0 m at 232 g/t Ag,

from 332.6m downhole, including 0.9 m at 956

g/t Ag

VANCOUVER, BC

,

Nov. 19, 2025

/CNW/ -

GR Silver Mining Ltd.

(

"

GR Silver Mining

" or the

"Company"

) (TSXV: GRSL) (OTCQB: GRSLF) (FRANKFURT: GPE) is pleased to announce

results from drill hole SMS25-12, extending the mineralization approximately 75 metres (m) below

the current San Marcial Resource Area ("Resource Area") (Figure 1) in the Plomosas Project. The

step-out drilling intersected two silver mineralized zones with multiple intervals of high-grade silver,

confirming the potential to expand the silver mineralization beyond the previous Resource Area

boundary (Figure 1) and remains open at depth.

Highlights of Step-Out Drilling at San Marcial

SMS25-12

intersected two distinct mineralized zones at shallow depth controlled by the

intersection of the NW-SE trending San Marcial breccia with N-S trending faults.

5.0 m

at 232 g/t Ag, from

332.6m

down hole, including

0.9 m

at 956 g/t Ag,

0.2 m

at 2,602 g/t Ag and

0.3 m

at 1,061 g/t Ag

8.8 m

at 121g/t Ag including

20 m

at 284 g/t Ag

SMS25-12

indicates continuity of the hydrothermal breccia structure for at least

400 m

below

surface. This bodes well for future resource expansion with another step-out drilling program

being planned for the first half of 2026.

High-grade silver values hosted by volcano-sedimentary units are creating additional drilling

targets at the footwall of chlorite-hematite rich breccias.

Multiple sets of N-S and NW-SE oriented structures are common in the San Marcial Area

creating prospective drill targets to guide the upcoming step-out drilling programs in 2026.

SMS25-11

intersected wide silver mineralization,

25 m

at 29 g/t Ag, suggesting that more

attractive silver mineralized zones may be hosted laterally to the recently reported SMS25-09

wide, high-grade intercept of

75 m

at 260 g/t Ag (see News Release dated

September 3, 2025

)

(Figure 2).

GR Silver Mining's President and CEO,

Marcio Fonseca

, commented,

"The recent success of step-

out drilling at the San Marcial Area in 2025 further strengthens our confidence in a large,

continuous silver-mineralized system at San Marcial. We are planning a significant step-out drilling

program in the first half of 2026 that could potentially double the existing silver mineralization

footprint to support resource growth at San Marcial."

Figure 1-Nov-19-2025 (CNW Group/GR Silver Mining Ltd.)

Table 1: SMS25-11 and SMS25-12 Drilling Highlights – 2025 Step-Out Drilling Program

Drill Hole

From

(m)

To

(m)

Type

Interval

(m)

Ag

g/t

Au

g/t

Pb

%

Zn

%

SMS25-11

382.8

407.4

Hydrothermal

Breccia &

Stockwork

24.6

29

0.01

0.1

0.1

(Incl)

390.3

399.2

Hydrothermal

Breccia &

Stockwork

8.9

49

0.02

NA

0.1

SMS25-12

300.7

310.3

Hydrothermal

Breccia

9.6

124

NA

0.1

0.2

(Incl)

307.3

309.3

Hydrothermal

Breccia

2.0

284

NA

0.1

0.5

332.6

337.6

Stockwork

5.0

232

0.02

NA

0.1

(Incl)

334.9

335.8

Stockwork

0.9

956

0.02

NA

0.1

Note:

Numbers may be rounded. Results are uncut and undiluted. True width not estimated as there is insufficient data from the new mineralized zones to determine the true

widths of the intervals with any confidence. NA = no significant result.

Step-out drilling completed at San Marcial in 2025 has confirmed the continuation of wide silver

mineralization, extending resource potential beyond the Resource Area (Figure 3). Hole SMS25-12

demonstrates the continuity of the silver mineralized system

150 m

beyond previous underground

drilling completed in 2021 (SMI21-04:

38 m

at 299 g/t Ag, including

3.5 m

at 1,002 g/t Ag, see

News Release dated

July 31

2022

) (Figure 2).

The confirmation of silver predominant mineralization, with low concentration of base metals, along

multiple N-S and NW-SE structures, provides additional targets for the upcoming step-out drilling

program planned for the first half of 2026 at the San Marcial Area (Figure 2). SMS25-12

demonstrates that the mineralization has continuity, not only in the chlorite-hematite hydrothermal

breccia but, also in the lower volcano-sedimentary unit where a quartz-calcite-sulfide veining with

silver is crosscutting early stage quartz-pyrite alteration, as shown in Figure 5.

SMS25-11, located

150 m

NW from SMS25-09, returned a wide intercept of

24.6 m

at 29 g/t Ag

indicating presence of wide silver mineralized zones hosted near major structures with intensive

hydrothermal alteration open for further investigation laterally and down-dip.

Figure2-Nov-19-2025 (CNW Group/GR Silver Mining Ltd.)

Figure3-Nov-19-2025 (CNW Group/GR Silver Mining Ltd.)

Figure4-Nov-19-2025 (CNW Group/GR Silver Mining Ltd.)

Figure5-Nov-19-2025 (CNW Group/GR Silver Mining Ltd.)

Table 2: 2025 San Marcial Step-Out Drill Program – Drill Hole Details

Drill Hole

Target

East (m)

North (m)

RL (m)

Dip (˚)

Azimuth (˚)

Depth

(m)

Results Status

SMS25-01

NW Extension

450685

2546064

914

-60

160

247.8

Abandoned

SMS25-02

NW Extension

450568

2546102

942

-55

135

206.0

Abandoned

SMS25-03

Parallel Breccia

450955

2545667

862

-60

135

206.0

Received

SMS25-04

Parallel Breccia

451045

2545757

860

-55

185

159.0

Received

SMS25-05

NW Extension

450791

2545967

892

-47

227

176.7

Received

SMS25-06

NW Extension

450797

2546016

895

-74

225

191.8

Received

SMS25-07A

Parallel Breccia

451145

2545641

795

-76

200

118.2

Received

SMS25-08

Parallel Breccia

451085

2545808

835

-65

175

244.5

Received

SMS25-09

SE Deep Extension

451506

2545924

700

-60

130

424.2

Received

SMS25-10A

Parallel Breccia

451506

2545924

700

-60

130

217.5

Received

SMS25-11

SE Deep Extension

451262

2545587

708

-81

143

407.35

Received

SMS25-12

SE Deep Extension

451313

2546012

799

-68

270

421.5

Received

SMS25-13

SE Deep Extension

451262

2545587

708

-62

280

383.0

Pending

Note: all holes drilled from surface; WGS84 Datum.

About the Plomosas Project

The Plomosas Project, including the recent high-grade silver discovery in the San Marcial SE Area,

is progressing in 2025 as an emerging high-grade silver district, located within the southwestern

edge of the Sierra Madre Occidental,

Sinaloa, Mexico

. The Plomosas Project covers 7,823 ha and

includes the historical Plomosas Underground Mine. The district contains intermediate to low-

sulfidation epithermal silver and gold mineralization, hosted in hydrothermal breccias and veins.

Recent success in exploration and drilling has delineated wide, high-grade, shallow hydrothermal

breccias in the San Marcial Area, including the SE Area discovery, where 2025 step-out drilling was

just completed. At the historical Plomosas Mine, operated by Grupo Mexico from 1985 to 2000,

underground sampling and metallurgical programs are being conducted to support future decisions

regarding the implementation of a Bulk Sampling Test Mining Program.

QA/QC Procedures

The Company has implemented QA/QC procedures, which include the insertion of blank, duplicate,

and standard samples in all sample lots sent to SGS de México, S.A. de C.V. laboratory facilities in

Durango, Mexico

, for sample preparation and assaying. For every sample with results above Ag >

100 ppm (over the limit), these samples are re-assayed by SGS de

Mexico

. Core samples are

represented by both HQ and NQ diameters and samples are represented by ½ core split of original

core. The analytical methods include four acid Digestion and Inductively Coupled Plasma Optical

Emission Spectrometry, with Lead Fusion Fire Assay and a gravimetric finish for silver above over

limits. For gold assays, the analytical methods are Lead Fusion and Atomic Absorption

Spectrometry, Lead Fusion Fire Assay, and gravimetric finish for gold above over limits (>10 ppm).

Qualified Person

The Qualified Person under National Instrument 43-101 Standards of Disclosure for Mineral Projects

for this news release is

Marcio Fonseca

, P. Geo., President & CEO for GR Silver Mining, who has

reviewed and approved its contents.

About GR Silver Mining Ltd

.

GR Silver Mining is a Canadian-based,

Mexico

-focused 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 the Plomosas Project, including the former Plomosas underground mine and wide,

high-grade silver mineralized zones at the San Marcial Area. Recent discoveries in the 78 km² of

highly prospective, advanced-stage exploration concessions position the Company well for resource

expansion at the Plomosas Project.

GR Silver Mining Ltd.

Márcio Fonseca, President & CEO

Cautionary Statement Regarding Forward-Looking Information

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.

View original content to download multimedia:

http://www.newswire.ca/en/releases/archive/November2025/19/c9470.html

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For further information:

For further information, please contact: Telephone: +1 236-270-2057,

Email: [email protected]

CO: GR Silver Mining Ltd.

CNW 06:00e 19-NOV-25