NIOB intersects higher-grade heavy rare earth mineralization at Seigneurie

NIOB’s Newest Seigneurie Assays Show Higher-Grade Heavy Rare Earth Mineralization

SGN-2026-003 returns 211.17 ppm dysprosium oxide over 2.0 metres within 946.25 ppm heavy rare earth oxide over 7.7 metres

Vancouver, British Columbia, July 14, 2026 (GLOBE NEWSWIRE) -- Assays from a second hole are in from North American Niobium and Critical Minerals Corp.’s (CSE: NIOB) (FSE: KS82.F) (OTCQB: NIOMF) (NIOB or the Company) Seigneurie Project, and the dysprosium grades are nearly three times higher than in the first, previously reported, hole. Hole SGN-2026-003 also returned the highest niobium oxide grade from the drilling to date and copper. This confirms that the Seigneurie pegmatite system, located in Quebec’s Grenville Province, includes a higher grade zone of mineralization that warrants follow up.

“This is the intercept we were watching for at Seigneurie,” said Murray Nye, NIOB’s Chief Executive Officer. “The niobium, dysprosium, and copper grades are a clear step up from the first results we reported from the project and sit within the same pegmatite system. It is one hole and the intervals are narrow, so we will let the assays and the updated geological model tell us what it means. However, this confirms that there is a higher-grade zone within the Seigneurie system, and that sharpens our targeting for the next phase of drilling.”

SGN-2026-003 Highlights

Niobium oxide: 4.75 m averaging 863.58 ppm niobium oxide (Nb₂O₅) from 71.15 to 75.90 m, the highest niobium grade reported from the Seigneurie drill program to date.

Dysprosium oxide: the hole returned 2.0 m averaging 211.17 ppm dysprosium oxide (Dy₂O₃) from 73.20 to 75.20 m within the niobium interval, nearly three times the dysprosium grade reported from hole SGN-2026-007.

Heavy rare earth oxide: the hole returned 7.7 m, averaging 946.25 ppm heavy rare earth oxide (HREO) from 71.15 to 78.85 m.

Copper: the hole returned 4.65 m averaging 910.89 ppm copper (Cu) from 74.20 to 78.85 m, adding a base-metal component to the mineralized system.

Higher-grade zone confirmed: all four composites cluster within a pegmatite hosted in the quartzofeldspathic gneiss sequence, confirming a coherent higher-grade zone that will guide follow-up drilling.

Next steps : completing assays for remaining Seigneurie drill holes, completing automated mineralogy study, and update geological model to target follow up drilling of higher-grade zone.

The niobium, dysprosium, HREO and copper composites overlap within an approximately 7.7-metre zone from 71.15 to 78.85 m core length centred on the pegmatite.

These results are from a single drill hole over narrow intervals, and additional work is required to determine whether the Seigneurie system hosts rare earth, niobium or copper mineralization of economic interest.

Figure 1 : Vertical cross-section through hole SGN-2026-003 (looking west), Seigneurie project, showing downhole Cu (left) and HREO (right) distributions and composite intervals.

Please click to view image

Figure 2 : Vertical cross-section through hole SGN-2026-003 (looking west), Seigneurie project, showing the mineralized pegmatite, downhole Dy₂O₃ (left) and Nb₂O₅ (right) distributions and composite intervals, and nearby NIOB surface samples.

Please click to view image

Composite intervals were calculated as length-weighted averages at cutoff grades of 500 ppm for Nb₂O₅, 100 ppm for Dy₂O₃, 500 ppm HREO, and 500 ppm for Cu, with interval boundaries at or above the cutoff grade and a maximum of 4 metres of internal dilution.

Rare earth oxide values are derived from elemental laboratory assays using standard stoichiometric conversion factors. Reported intervals are core (downhole) lengths.

True widths have not yet been determined and will be estimated once the geological model is updated with the remaining drill-hole data.

Drilling and geological context Hole SGN-2026-003 was collared at 480732E 5381978N, UTM NAD83 Zone 18, and drilled at an azimuth of 10° and a dip of approximately -45° to a total depth of approximately 227 m.

The hole intersected a sequence dominated by quartzofeldspathic gneiss with intervals of gneiss, amphibolite and pegmatite; the higher-grade composites are hosted in and immediately below a pegmatite intersected at approximately 71.15-78.85 m core length.

Next Steps 1. Complete assays for the remaining Seigneurie drill holes and update the geological model, including estimates of true widths. 2. Complete the automated mineralogy (TIMA) study to determine the mineral hosts and deportment of the rare earths and niobium. 3. Integrate the SGN-2026-003 results into targeting for follow-up drilling of the higher-grade zone. 4. Advance systematic exploration across the Company’s broader Québec portfolio, prioritizing the highest-quality niobium and rare earth targets.

Quality Assurance and Quality Control Samples were submitted to SGS Canada Inc. Rare earth elements were determined by sodium-peroxide-fusion ICP-MS (SGS method GE_IMS91A50), niobium by fused-bead XRF (GO_XRF72NB) and copper by sodium-peroxide-fusion, nitric acid, ICPAES (GE_ICP91A50).

Within the mineralized interval, the yttrium (Y) assay result exceeded the laboratory's upper limit of detection (1,000 ppm). A value of 1,000 ppm — the maximum reportable concentration — was used in calculating the reported HREO grade. As a result, the true yttrium content, and therefore the reported HREO grade of 946.25 ppm over 7.7 m, may be understated.

Quality control included certified reference materials, blanks and field duplicates inserted into the sample stream (approximately 13% of submitted samples). The reported samples are NQ-size half-core, split along the core axis and sampled over intervals of approximately 0.5 to 1.0 m, with the remaining half-core retained for reference.

Core recovery through the mineralized intervals averaged approximately 90–98% and is not considered to have materially affected sample representivity. SGS Canada Inc. is independent of the Company and operates an ISO/IEC 17025-accredited analytical facility at Val-d’Or, Québec.

Qualified Person The scientific and technical information contained in this news release has been prepared in accordance with National Instrument 43-101 – Standards of Disclosure for Mineral Projects (NI 43-101). Clyde McMillan, P.Geo., a consultant to the Company and a Qualified Person as defined under NI 43-101, has reviewed and approved the technical information contained herein.

The Qualified Person has verified the data disclosed in this release by reviewing the SGS Canada Inc. analytical certificates and the Company’s quality-control results and reconciling the reported values to the laboratory certificates. No limitations to the data verification were identified.

ABOUT NORTH AMERICAN NIOBIUM AND CRITICAL MINERALS CORP. North American Niobium and Critical Minerals Corp. is a North American mineral exploration company focused on the acquisition and development of precious, base, and critical mineral assets. Its portfolio includes the Silver Lake property in British Columbia’s Omineca Mining Division and a district-scale land package covering 29,936 hectares in Quebec’s Grenville Province. The Quebec properties host rare earth element, niobium, and nickel-copper occurrences, expanding the Company’s footprint into critical minerals that are strategically important for energy and defense applications.

ON BEHALF OF THE BOARD OF DIRECTORS: Murray Nye Chief Executive Officer info@northamericanniobium.com +1 (647) 984-4204

FORWARD LOOKING STATEMENTS This news release contains “forward-looking statements” within the meaning of applicable Canadian securities legislation. All statements in this release, other than statements of historical fact, that address events, results, outcomes or developments that the Company expects, anticipates or intends to occur in the future, or that otherwise reflect management’s expectations or beliefs about future events, are forward-looking statements. Forward-looking statements are generally, but not always, identified by the use of words and phrases such as “expects,” “plans,” “anticipates,” “believes,” “intends,” “estimates,” “projects,” “potential,” “strategy,” “target” and similar expressions, or statements that events, conditions or results “will,” “would,” “may,” “could,” or “should” occur or be achieved.

Forward-looking statements in this release include, but are not limited to:

the completion, timing and outcomes of the planned automated mineralogy (TIMA) study and its bearing on the deportment of niobium and the rare earths;

the Company’s intention to update the Seigneurie geological model and estimate true widths;

the planning and execution of follow-up drilling at Seigneurie, including drilling of the higher-grade zone;

the Company’s intention to advance exploration across its broader Québec portfolio and to prioritize niobium and rare earth targets; and

expectations regarding rare earth, niobium and copper markets. Such forward-looking statements are based on the Company’s current plans, intentions, expectations and beliefs and are subject to assumptions, including that exploration results will continue to support the prospectivity of the properties.

Although the Company believes the expectations expressed in such forward-looking statements are reasonable, such statements are not guarantees of future performance or outcomes and actual results may differ materially from those expressed or implied. Factors that could cause actual results to differ materially include, but are not limited to: assay, mineralogical and metallurgical results differing from expectations or from field observations; the timing and receipt of laboratory results; the inherent uncertainty of mineral exploration; changes in commodity prices and market conditions, including rare earth and niobium prices; the availability of capital and financing on acceptable terms; general economic, business and political conditions; environmental and operational risks; changes in government regulation or policy; and the speculative nature of mineral exploration and development. Additional information regarding risks and uncertainties is available in the Company’s public disclosure record on SEDAR+ ( www.sedarplus.ca ).

Readers are cautioned that forward-looking statements are not guarantees of future performance and undue reliance should not be placed on them. The forward-looking statements in this release are made as of the date hereof and are based on information currently available and management’s beliefs, estimates and opinions at that time. Except as required by applicable securities laws, the Company undertakes no obligation to update or revise any forward-looking statements.

The Canadian Securities Exchange does not accept responsibility for the adequacy or accuracy of this release and has neither approved nor disapproved the contents of this press release.