GRSL.V · 2023-03-20 12:00:00

GR Silver Announces Significant Updated Mineral Resource Estimate for the Plomosas Project 97 Moz Indicated and 53 Moz Inferred - Silver Equivalent

Resource Estimates

GR Silver Announces Significant Updated

Mineral Resource Estimate for the Plomosas

Project 97 Moz Indicated and 53 Moz Inferred -

Silver Equivalent

VANCOUVER, BC

March 20, 2023

/CNW/ -

GR Silver Mining Ltd.

GR Silver Mining

" or the

Company

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

independent, updated Mineral Resource Estimate (the "Resource Estimate") in accordance with

National Instrument 43-101 Standards of Disclosure for Mineral Projects ("NI 43-101") for the

Company's wholly-owned Plomosas Project in

Sinaloa, Mexico

. The Resource Estimate was

completed by ARSENEAU Consulting Services Inc, ("ACS") of

Vancouver, British Columbia

, Canada,

and integrates resources for the San Marcial, Plomosas Mine and San Juan-La Colorada Areas

within the Plomosas Project.

Highlights of the Resource Estimate (Table 1) including comparison to the

previous mineral resource estimates

are:

108% increase in indicated mineral resources from 46 Moz to 97 Moz silver equivalent

("AgEq")

72% increase in indicated mineral resources from 32 Moz to 55 Moz Ag

61% increase in inferred mineral resources from 33 Moz to 53 Moz AgEq

20% increase in inferred mineral resources from 18 Moz to 22 Moz Ag

44% increase in average indicated mineral resource grade from 143 to 206 g/t AgEq

65% increase in average inferred mineral resource grade from 112 to 185 g/t AgEq

San Marcial Area

80% increase in indicated mineral resources from 36 Moz to 65 Moz AgEq

65% increase in inferred mineral resources from 12 Moz to 20 Moz AgEq

Indicated mineral resources of 9.7 Mt at 209 g/t AgEq (148 g/t Ag)

Inferred mineral resources of 3.0 Mt at 200 g/t AgEq (145 g/t Ag)

71% of the value of the San Marcial Resource Estimate is comprised of silver

91% of the 65 Moz AgEq San Marcial indicated resources are potentially amenable to open pit

extraction

True width of the modelled San Marcial mineralization averages 22 metres, while the SE Area

discovery averages 53 metres in thickness, supporting potential for low-cost bulk mineable open

pit and/or underground mining methods

____________________

San Marcial 2019 resource (see News Releases dated February 7, 2019 and June 12, 2020); Plomosas Mine and San Juan 2021 resource (see News Release dated August 23,

2021)

Refer to footnote below Tables 1 and 2 for AgEq definition

Plomosas Mine Area

2022 infill drilling resulted in an increase of 137% in the indicated mineral resource tonnage

260% increase in indicated mineral resources from 9 Moz to 31 Moz AgEq

Ag and AgEq grade increased by 30% and 52%, respectively, in indicated mineral resources in

relation to the previous resource estimate

Ag ounces represent 20% of total indicated mineral resources at the Plomosas Mine Area

Ag ounces represent 26% of total inferred mineral resources at the Plomosas Mine Area

True width of modelled mineralization at the Plomosas Mine Area averages 20 metres,

supporting potential for low-cost bulk mineable open pit and/or underground mining methods

46% of the value of the Resource Estimate at the Plomosas Mine Area is comprised of precious

metals

Key Statistics

GR Silver Mining has successfully expanded resources at a low cost of exploration and

acquisition (

US$0.25

/oz) at the Plomosas Project

Since previous resource estimates in 2019 and 2021, the Company has achieved an estimated

exploration cost of

US$0.17

/oz AgEq discovered

Indicated AgEq and Ag ounces have increased 331% and 206% since the Company's inception

Inferred AgEq and Ag ounces have increased 632% and 406% since the Company's inception

The proportion of total indicated resource (oz AgEq) has increased since the previous resource

estimate, now representing 65% of total resources at the Plomosas Project (Figure 1).

Figure 1 Resource Growth

Figure 1 - Resource Growth (CNW Group/GR Silver Mining Ltd.)

GR Silver Mining Chairman and CEO,

Eric Zaunscherb

comments,

We are very pleased to

achieve this milestone as promised over the past year. The conservative parameters applied, and

the approach taken, allow us to be confident in this positive outcome as we focus on broad zones

of mineralization that may be amenable to bulk, low-cost open pit and/or underground mining

methods. Delivery of this Resource Estimate continues the advance and de-risk process for the

Plomosas Project. Management will now turn to planning next steps, which will build on already

robust resource growth, tapping into the property's significant exploration potential.

Only

approximately 300 metres of the SE Area discovery zone has been drilled of 6 kilometres

prospective contact strike length,100% controlled by the Company. Recent surface mapping by our

geologists has peeled the geological onion and discerned the controls on high-grade

mineralization for future success.

In addition, we intend to begin attaching economic parameters to

the Plomosas Project that, in our opinion, will demonstrate its appeal. We are very proud of, and

grateful to, our team of employees and consultants at site for making this possible.

A total of 75 GR Silver Mining drill holes (10,500 metres) were added to the 52 holes used in the

previous resource estimate, totalling 122 holes (19,000 metres) for the San Marcial Area including

SE Area discovery. At the Plomosas Mine Area, a total of 223 drill holes (16,380 metres) were

drilled in specific areas of the existing underground historical mine as part of the infill drilling

program. A total of 424 drill holes (60,020 metres) comprises the Plomosas Mine Area database

supporting the Resource Estimate.

In addition to the San Marcial and Plomosas Mine Areas, the Resource Estimate also includes the

updated mineral resource estimation for the San Juan-La Colorada Area (Figure 2). The Plomosas

Project Resource Estimate combines the three areas and includes the SE Area discovery. The

Resource Estimate adopts the key parameter of having a reasonable prospect of economic

extraction, utilizing a combination of open pit and underground assumptions. Capping was applied to

the original assay values prior to compositing in the mineral resource estimation process (Table 4).

A technical report is being prepared on the updated Mineral Resource Estimate in accordance with

NI 43-101 and will be available on the Company's website and SEDAR within 45 days of the date of

this release. The effective date of the updated Mineral Resource Estimate is

March 15, 2023

Figure 2 Location of the Three Areas Integrated in the Plomosas Project Resource Estimate

Figure 2 - Location of the Three Areas Integrated in the Pllomosas Project Resource Estimate

(CNW Group/GR Silver Mining Ltd.)

The San Marcial Area, including the SE Area discovery, with indicated mineral resources of 9.7 Mt

at 209 g/t AgEq (148 g/t Ag) and inferred mineral resources of 3.0 Mt at 200 g/t AgEq (145 g/t

Ag) represents approximately 78% of Ag contained in the total Resource Estimate. Shallow infill

drilling during 2022 in the 2019 resource area has enhanced the definition of high-grade silver zones

close to surface within the San Marcial mineral resource, which is reflected in Table 2, defining the

potential for an open pit amenable portion of the San Marcial Area resource estimate.

Infill drilling in the previous resource area of the Plomosas Mine during 2022 has enhanced the

definition of silver grades particularly closer to the surface, at shallow levels of the historic

underground mine, where the Company achieved better delineation of high-grade Ag zones. At the

lower levels of the historic underground mine, the Pb-Zn mineralization continues to provide a strong

contribution to the Resource Estimate. Overall, the average silver grades for indicated and inferred

resources in the Resource Estimate for the Plomosas Mine Area are slightly higher than the 2021

resource estimate. This is reflected in the detailed summary of the Plomosas Mine Area resource

statement in Table 2.

The Resource Estimate for the San Juan-La Colorada Area consists primarily of an update in the

geological model and limited drilling to integrate newly interpreted structural controls into the

resource estimation. A slight increase in the gold grades can be observed, particularly at

Colorada

, resulting from a more detailed modelling, when compared with the previous resource

estimate.

Table 1 Plomosas Project Mineral Resource Statement ACS -

March 15, 2023

Average Grade

Contained Metal

PLOMOSAS

Resource

Type

Tonnes

AgEq*

AgEq

PROJECT

Category

g/t

Moz

Koz

Moz

San Marcial Area

Indicated

146

0.04

0.2

0.3

205

10.2

Inferred

127

0.03

0.1

0.2

173

1.4

Indicated

176

0.06

0.3

0.6

258

1.5

Inferred

164

0.03

0.2

0.4

229

1.6

Total

Indicated

148

0.04

0.2

0.3

209

11.7

Total

Inferred

145

0.03

0.1

0.3

200

3.0

Plomosas Mine Area

Indicated

0.24

1.0

0.9

0.07

193

11.9

Inferred

0.28

1.0

0.06

174

7.8

Indicated

0.57

0.9

1.3

0.08

204

58.0

Inferred

0.57

0.9

1.1

0.06

175

39.4

Total

Indicated

0.46

1.0

1.2

0.08

200

69.9

Total

Inferred

0.48

0.9

1.0

0.06

175

47.2

San Juan-La Colorada Area

Indicated

0.1

161

0.29

0.3

0.6

0.02

211

0.4

0.8

Inferred

0.2

104

0.24

0.5

0.8

0.02

158

0.7

1.5

Indicated

0.1

0.61

1.1

0.8

0.04

198

0.3

2.1

Inferred

2.6

0.69

1.2

1.9

0.04

182

2.8

56.4

Total

Indicated

0.2

121

0.46

0.7

0.03

204

0.8

2.9

Total

Inferred

2.8

0.65

1.1

1.8

0.04

180

3.5

57.9

Numbers are rounded

* AgEq = calculated from the metal prices and recoveries using the equation AgEq = ((Au price*Au Recovery) + (Ag Price*Ag Recovery) + (Pb Price*Pb Recovery) + (Cu Price*Cu

Recovery) + (Zn Price*Zn Recovery)) / (Ag Price*Ag Recovery)

(1) Mineral Resources which are not Mineral Reserves, do not have demonstrated economic viability

(2) The estimate of Mineral Resources may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues

(3) The Inferred Mineral Resource in this estimate has a lower level of confidence than that applied to an Indicated Mineral Resource and must not be converted to a Mineral

Reserve. It is reasonably expected that the majority of the Inferred Mineral Resource could be upgraded to an Indicated Mineral Resource with continued exploration

(4) The Mineral Resources were estimated using the Canadian Institute of Mining, Metallurgy and Petroleum (CIM), CIM Standards on Mineral Resources and Reserves,

Definitions and Guidelines prepared by the CIM Standing Committee on Reserve Definitions and adopted by the CIM Council

Mineral Resource Estimates

The mineral resource estimates for the San Marcial, Plomosas Mine, San Juan-La Colorada Areas

were provided by Dr.

Gilles Arseneau

, P.Geo. of ARSENEAU Consulting Services Inc. (ACS) using

Geovia Gems Version 6.8.4. The San Marcial and Plomosas Mine mineral resources were

estimated by ordinary kriging, and the

San Juan

La Colorada

mineral resources were estimated by

the Inverse Distance Squared method. The Plomosas and

San Juan

models were estimated in 5

metre cube blocks and the San Marcial grades were estimated in 10 by 5 by 10 metre blocks.

Grades were capped to the 98

or 99

percentile from probability plots prior to compositing to 1

metre. Block grades were estimated in three successive passes for the San Marcial and Plomosas

Mine and four passes for the San Juan-La Colorada Area. The historical Grupo Mexico drill holes

were only used for passes two and three at the Plomosas Mine and for passes three and four at the

San Juan-La Colorada Area. Blocks estimated with Grupo Mexico drill holes were all classified as

inferred mineral resources. Blocks estimated during Pass 1 with at least two drill holes or Pass 2 at

San Juan

, with at least four drill holes, were classified as Indicated.

Mineral resources are reported using a dollar equivalent based on the following metal prices and

recoveries determined from recent metallurgical tests. The mineral resources are reported using pit

constrained ("Whittle Pit Assessment") and Underground stope optimizer ("MSO") with operational

cost assumptions reported in Table 3.

Table 3 Summary Parameters Adopted for Resource Estimation and Mineral Resource

Reporting - Plomosas Mine and San Juan Areas

Plomosas Project

Metal Prices

Gold US$/oz

$1,750

Silver US$/oz

$22.00

Lead US$/lb

$1.10

Zinc US$/lb

$1.30

Copper US$/lb

$4.20

rea

San Marcial

Plomosas Mine

San Juan

Metallurgical Recoveries***

Gold

86 %

79 %

Silver

94 %

74 %

71 %

Lead

59 %

69 %

58 %

Zinc

80 %

75 %

47 %

Preliminary Cost Assumptions

Mineral Resource Reporting****

Open Pit ("OP")

30 US$/t

Underground ("UG")

60 US$/t

*** Based on preliminary metallurgical testwork completed in 2021 with samples from both areas investigating potential production of precious metal-rich concentrate

**** Preliminary cost assumptions adopted in the Whittle assessment and MSO are based on similar type deposits in Mexico where underground and open pit operations are in

progress for a throughput capacity of 1000 tpd

Capping was adopted in the Resource Estimate by each specific domain as indicated in Table 4.

The reasonable prospect of economic extraction was defined by generating a Whittle optimized pit

shell based on the above metal prices and recoveries and assuming a total open pit mining cost and

processing cost of

US$30

/t. Underground resources were restricted to shapes defined by stope

optimizer software and assumed combined underground mining and processing costs of

US$60

/t.

The mineral resource estimates are based upon drilling completed by the Company between 2021

and 2022.

Table 4 Plomosas Project – Assay Capping Level by Area

Metal

San Marcial

Silver Zone

San Marcial

Pb-Zn Zone

Plomosas

US$20 Zone (DDH)

Plomosas

Pb-Zn Zone (DDH)

San Juan

La Colorada

Gold

15.0 g/t

2.5 g/t

3.0 g/t

5.0 g/t

Silver

1,800 g/t

850 g/t

800 g/t

200 g/t

825 g/t

350 g/t

Copper

1.0 %

0.5

Lead

4.5 %

20.0 %

6.5 %

4.0 %

10.0 %

Zinc

5.0 %

15.0 %

8.3 %

8.0 %

13.0 %

DDH = drill holes

NC=no capping applied

QA/QC Procedures

The Company has implemented QA/QC procedures which include 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 limits), these samples are submitted directly by SGS de

Mexico

to SGS Canada

Inc. at

Burnaby, BC

. The analytical methods are four acid Digest and Inductively Coupled Plasma

Optical Emission Spectrometry with Lead Fusion Fire Assay with 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 mineral resource estimate was completed by independent consultant Dr

Gilles Arseneau

, P.

Geo. of ARSENEAU Consulting Services Inc., a registered professional, who is an independent

Qualified Person (QP) as defined by NI 43-101. Mineral resources are reported in accordance with

CIM (2014) Definition Standards for Mineral Resources and Mineral Reserves in accordance with NI

43-101. Dr. Arseneau is a P. Geo. and is qualified as a Mineral Resource estimator and has over 25

years of relevant industry experience.

The scientific and technical data contained in this News Release related to the Plomosas Project

was reviewed and/or prepared under the supervision of

Marcio Fonseca

, P. Geo. He has approved

the disclosure herein.

About GR Silver Mining Ltd

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 square kilometres of concessions containing several structural corridors totaling

over 75 kilometres in strike length.

GR Silver Mining Ltd.

Eric Zaunscherb, Chairman & 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/March2023/20/c9997.html

%SEDAR: 00040149E

For further information:

Brenda Dayton, VP Corporate Communications, Telephone:

+1.604.417.7952, Email: [email protected]

CO: GR Silver Mining Ltd.

CNW 06:15e 20-MAR-23

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