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MONUMENTAL MINERALS CORP. PROVIDES EXPLORATION UPDATE AND DEFINES DRILL TARGETS AT THE JEMI HEAVY RARE EARTH ELEMENT PROJECT, MEXICO Results Include 2.4% Total Rare Earth Oxide And 0.94% Heavy Rare Earth Oxide

Drill Results Exploration Programs

MONUMENTAL MINERALS CORP. PROVIDES EXPLORATION UPDATE AND

DEFINES DRILL TARGETS AT THE JEMI HEAVY RARE EARTH ELEMENT

PROJECT, MEXICO

Results Include 2.4% Total Rare Earth Oxide And 0.94% Heavy Rare Earth Oxide

News Release - Vancouver, British Columbia – February 23, 2023: Monumental Minerals Corp.

(“Monumental” or the “ Company”) (TSX -V: MNRL; FSE: BE5; OTCQB: MNMRF) is pleased to

provide an update on exploration at the Jemi rare earth element (REE) project (the “Project”) located in

Coahuila, Mexico, about 40 km south of the Texas, USA border . Rock sampling across a broad area has

discovered high grades of the critical magnet metals dysprosium (Dy) and terbium (Tb) and defined a series

of high priority drill targets.

Four months of exploration has been completed at Jemi, with the objective to delineate discreet drill targets.

Recent work consisted of detailed geological mapping, regional stream sediment sampling, ground

radiometric geophysical surveys, and lithogeochemical sampling. Exploration focused on the Jemi Dykes

and Veladora North areas, which host peralkaline intrusion related REE mineralization.

To date, 188 assays from rocks collected at Jemi Dykes and Veladora North have been received while

results for 177 samples from Veladora North are pending. Of the 188 samples with assay results, over one

third (76 samples) returned values greater than 0.15% total rare earth oxide (TREO1), including 5 samples

that returned values greater than 1.0% TREO1 to a maximum value of 2.4% TREO1 (sample number 22309)

(Table 1). The average TREO for all samples is 0.21%, and a minimum value of 9 parts per million (ppm),

which was returned in an iron-oxide/calcite vein.

Dysprosium oxide (Dy2O3) and terbium oxide (Tb2O3) in samples classified as peralkaline rang e between

959 ppm and 3 ppm; and 147 ppm and 0.6 ppm, respectively. The average concentration for Dy2O3 is 83

ppm; and the average for Tb2O3 is 13 ppm. Light rare earth oxides, namely neodymium oxide (Nd2O3) and

praseodymium oxide (Pr2O3), return values that range between 3173 ppm and 19 ppm; and 824 ppm and

5.5 ppm, respectively. The average concentration for Nd2O3 is 359 ppm; and for Pr2O3 it is 103 ppm.

Heavy rare earth oxide (HREO2) concentration greater than the 75th percentile is 1062 ppm in peralkaline-

classified rocks (31 samples), including ten that exceed 2500 ppm. These values are in trend with LREO3

concentrations and the ratio of HREO 2 to LREO3 is consistently on average 1:2, suggesting similar REE-

hosting phases in the peralkaline rock samples.

Dr. Jamil Sader, CEO and Director comments:

“Mapping, sampling and geophysics at Jemi Dykes and Veladora North has resulted in the

definition of a new previously unknown zone of mineralized dykes. Of most significance, we have

discovered what we believe to be some of the highest grades of HREO, including the magnet metals

dysprosium and terbium, of any rocks in North America. We anticipate having drill locations

mapped out at both the Jemi Dykes and Veladora North areas before Q2 2023.”

1 Total Rare Earth Oxides (TREO) includes: La2O3, Ce2O3, Pr2O3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Tb2O3, Dy2O3, Ho2O3, Er2O3,

Tm2O3, Yb2O3, Lu2O3, Y2O3.

2 Heavy Rare Earth Oxides (HREO) includes: Eu2O3, Gd2O3, Tb2O3, Dy2O3, Ho2O3, Er2O3, Tm2O3, Yb2O3, Lu2O3, Y2O3,

3Light Rare Earth Oxides (LREO) includes La2O3, Ce2O3, Pr2O3, Nd2O3, Sm2O3.

Rock samples with the highest REE content are those that are classified as peralkaline (sodium plus

potassium concentrations are greater than aluminum concentrations). In most hard rock HREE ore deposits,

rocks must be pe ralkaline in order for HREE bearing silicate minerals such as eudialyte to crystalize.

Eudialyte is the dominant REE host mineral at Jemi, that can contain up to 10% RE 2O3 (enriched in

HREEs), and 12% ZrO2.

In addition to being REE -mineralized, samples a re also mineralized with respect to tantalum (Ta) and

niobium (Nb). Laboratory determination of these critical elements in all samples from the Jemi project

return values to 975 ppm Ta 2O5 and greater than (>) 3576 ppm Nb 2O5, with an average concentration of

Ta2O5 of 60 ppm and Nb2O5 of 665 ppm.

At the Jemi Dykes area, the highest REE concentrations are from eudialyte +/- aegirine rich dykes that are

clustered in an approximately 150 m wide; 1600 m long zone oriented parallel to the La Vasca intrusive

complex (Figure 1). These mineralized dykes are commonly between 0.5 to 2 m in width, with the higher

grade ones situated in the southern part of the survey area. Three-dimensional airborne magnetics modeling

suggests that magma sources for the mineralized dykes are at a shallow depth (less than 300 m), and that

they are spatially associated with the 150 m wide zone of mineralized dykes observed at the surface. These

zones of favourable dyke geology, lithogeochemistry, and geophysics will be the focus of drilling.

Table 1. Top 15 assay results for rare earth elements and other critical metals from the Jemi Dykes and Veladora

North area of the Jemi Project. Rock grab samples are selective samples by nature and as such are not

necessarily representative of the mineralization hosted across the Jemi Project.

Rare Earth Element Value and Applications for the Energy Transformation

Because of their unusual physical and chemical properties, the REEs have diverse defense, energy,

industrial, and military technology applications. Demand for REEs is expected to outstrip supply in less

than 2 years, and it is expected that there will be a shortage of the metals until at least 20302 - dominantly

due the increase in demand for neomagne ts for EV motors, as well as other types of electric motors (e.g.,

wind turbines, water pumps). Neodymium-iron-boron magnets, which are the strongest known type of

magnets, are used when space and weight are restrictions are present. The addition of HREEs terbium or

dysprosium to magnets can double their optimal operating temperature from 80 °C to 160°C. In addition,

2 Macquarie Rare Earth Market Research, December 9, 2021

SAMPLE_ID Location TREO HREO LREO Nd2O3 Pr2O3 Tb2O3 Dy2O3 Ta2O5 Nb2O5 Rock Type

(%) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm)

22309 La Veladora 2.4 9406 14413 3173 824 147 959 976 >3578 Peralkaline

22313 La Veladora 1.5 6179 8437 2030 496 97 607 676 2948 Peralkaline

22350 La Veladora 1.1 3663 6873 1487 405 57 356 374 >3578 Peralkaline

22339 La Veladora 1.0 2455 7594 1324 406 38 234 198 2032 Peralkaline

22295 Jemi Dykes 1.0 3228 6791 1121 334 41 303 335 >3578 Peralkaline

22344 La Veladora 0.9 2791 6607 1271 364 42 269 252 2390 Peralkaline

22256 Jemi Dykes 0.9 2559 6696 1149 362 37 250 223 >3578 Peralkaline

22248 Jemi Dykes 0.8 3538 4919 938 270 48 337 460 >3578 Peralkaline

22265 Jemi Dykes 0.8 2665 5555 907 264 36 236 241 2962 Peralkaline

22335 La Veladora 0.8 2595 5465 1095 295 42 262 221 1175 Peralkaline

22278 Jemi Dykes 0.8 2380 5673 974 279 33 217 212 2583 Peralkaline

22252 Jemi Dykes 0.7 2553 4692 850 256 35 249 236 2762 Peralkaline

22392 La Veladora 0.7 1769 5305 963 281 26 169 211 3077 Peralkaline

22258 Jemi Dykes 0.7 2062 4836 828 236 28 181 187 3449 Peralkaline

22322 La Veladora 0.7 2325 4399 961 243 37 226 324 2655 Peralkaline

dysprosium with praseodymium increases a magnet’s coercivity (the resistance of a magnetic material to

change in magnetisation).

The four key REEs represent 94% of the REE market by value (Nd, Pr, Dy, and Tb ), all of which are

enriched at Jemi. Concentrations of Nb and Ta also meet the threshold to be considered potentially

economically significant (Table 2).

Table 2. Current spot prices for oxide Nd/Pr/Dy/Tb, Nb, and Ta.

Figure 1. Map of 3D airborne geophysical anomaly (see Company’s news release dated May 3, 2022) interpreted to

represent a magmatic intrusion at the Jemi Dykes area, which is likely the source of mineralized peralkaline dykes

mapped at surface. Heavy rare earth oxides are as high as 3228 ppm in these rocks and present highly favourable

drilling targets.

Oxide Metal Nd2O3 Pr2O3 Tb2O3 Dy2O3 Nb2O3 Ta2O3

Current Spot Price (USD/kg) $117.42 $104.46 $2,081.73 $364.49 $43.50 $250.00

Spot Price Source Ginger International Trade & Investment Pt Institut Seltene Erden

Methodology and QA/QC

The analytical work reported on herein was performed by ALS Canada Ltd. (ALS) at Hermosillo, Mexico

(sample preparation) and Vancouver, B.C. (ICP -MS fusion). ALS is an ISO -IEC 17025:2017 and ISO

9001:2015 accredited geoanalytical laboratory and is independent of Monumental Minerals and the QP.

Rock samples were subject to crushing at a minimum of 70% passing 2 mm, followed by pulverizing of a

250-gram split to 85% passing 75 microns. A 0.1-gram sample pulp was then subject to multi-element ICP-

MS analysis via lithium -borate fusion to determine individual REE content (ME -MS81). Monumental

Minerals quality assurance/quality control (QA/QC) program for field rock samples includes the insertion

of certified reference standards into the sample sequence to confirm the accuracy of the reported results.

Monumental Minerals detected no significant QA/QC issues during review of the data, and is not aware of

any sampling, or other factors that could materially affect the accuracy of the results.

Qualified Person

The scientific and technical information contained in this news release has been reviewed and approved

by Kristopher J. Raffle, P.Geo. (BC) Principal and Consultant of APEX Geoscience Ltd. of Edmonton, AB,

a Director of the Company and a “Qualified Person” as defined in National Instrument 43-101 – Standards

of Disclosure for Mineral Projects. Mr. Raffle verified the data disclosed which includes a review of the

sampling, analytical and test data underlying the information and opinions contained therein.

About Monumental Minerals Corp.

Monumental Minerals Corp. is a mineral exploration company focused on the acquisition, exploration, and

development of mineral resource properties in the critical and electric metals sector. The Company’s

flagship asset is the Jemi HREE project located in Coahuila, Mexico near the Texas, USA border which the

Company has an option to acquire 100% of the 3,650-hectare project. The Company has an option to acquire

a 75% interest and title to the Laguna cesium-lithium brine project located in Chile and a 50.01% interest

in the Salar De Turi lithium project in Chile.

On behalf of the Board of Directors,

/s/ “Jamil Sader”

Jamil Sader, Chief Executive Officer and Director

Contact Information:

Email: [email protected]

Or

Max Sali, VP Corporate Development and Director

Email: [email protected]

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 news

release.

Forward Looking Information

This news release contains “forward‐looking information or statements” within the meaning of applicable securities

laws, which may include, without limitation, the potential plans for the Company’s projects, receipt of additional assay

results from Jemi, the expected timing and completion of potential drilling at Jemi, other statements relating to the

technical, financial and business prospects of the Company, its projects and other matters. All statements in this news

release, other than statements of historical facts, that address events or developments that the Company expects to

occur, are forward-looking statements. Although the Company believes the expectations expressed in such forward -

looking statements are based on reasonable assumptions, such statements are not guarantees of future performance

and actual results may differ materially from those in the forward-looking statements. Such statements are based on

numerous assumptions regarding present and future business strategies and the environment in which the Company

will operate in the future, including the price of metals, the ability to achieve its goals, that general business and

economic conditions will not change in a material adverse manner and that financing will be available if and when

needed and on reasonable terms. Such forward -looking information reflects the Company’s views with respect to

future events and is subject to risks, uncertainties and assumptions, including the risks and uncertainties relating to the

interpretation of exploration results, risks related to the inherent uncertainty of exploration and cost estimates and the

potential for unexpected costs and e xpenses and those other risks filed under the Company’s profile on SEDAR at

www.sedar.com. While such estimates and assumptions are considered reasonable by the management of the

Company, they are inherently subject to significant business, economic, competitive and regulatory uncertainties and

risks. Factors that could cause actual results to differ materially from those in forward looking statements include, but

are not limited to, continued availability of capital and financing and general economic, market or business conditions,

failure to secure personnel and equipment for work programs , adverse weather and climate conditions, risks relating

to unanticipated operational difficulties (including failure of equipment or processe s to operate in accordance with

specifications or expectations, cost escalation, unavailability of materials and equipment, government action or delays

in the receipt of government approvals, industrial disturbances or other job action, and unanticipated events related to

health, safety and environmental matters), risks relating to inaccurate geological assumptions, failure to maintain all

necessary government permits, approvals and authorizations, failure to obtain surface access agreements or

understandings from local communities, land owners or Indigenous groups, fluctuation in exchange rates, the impact

of Covid-19 or other viruses and diseases on the Company’s ability to operate, an inability to predict and counteract

the effects of COVID-19 on the business of the Company, including but not limited to, the effects of COVID -19 on

the price of commodities, capital market conditions, restriction on labour and international travel and supply chains,

decrease in the price of rare earth elements, lithium, cesium and other metals, loss of key employees, consultants, or

directors, failure to maintain community acceptance (including from the Indigenous communities), increase in costs,

litigation, and failure of counterparties to perform their contractual obligations . The Company does not undertake to

update forward‐looking statements or forward‐looking information, except as required by law.