Ms. Marcy Kiesman reports

QUANTUM CRITICAL METALS CONFIRMS GALLIUM & RUBIDIUM ARE HOSTED IN MICA AT ITS DISCOVERY PROPERTY, QUEBEC, AND IDENTIFIES NEW BERYLLIUM AND CESIUM TARGETS

Quantum Critical Metals Corp. has released results of advanced laser mineral mapping on nine historical samples from its wholly owned Discovery property in the Eeyou Istchee James Bay region of Quebec.

The work shows that gallium and rubidium at Discovery are held mainly in mica, the same host mineral the company is working with at its flagship NMX East project. Because the company has already developed its approach to recovering gallium and rubidium from mica at NMX East, it can apply that experience directly at Discovery rather than starting from first principles. The study also identified strong beryllium and cesium responses in two separate samples, which are potential additional upsides that the company will investigate further.

Highlights:

• Gallium is hosted in mica: Gallium was detected in all nine samples. In eight of the nine, the gallium response closely tracked the amount of mica present.
• Rubidium is hosted in mica and feldspar: Rubidium closely followed the combined amount of potassium-bearing mica and feldspar, with a very strong statistical relationship.
• Same host as NMX East: Mica is the same host mineral as at NMX East, where the company has built its gallium and rubidium recovery approach.
• New beryllium target: One sample returned a beryllium response about 21 times the median of the other samples in a different rock type from the rubidium-bearing pegmatites.
• New cesium target: A separate sample returned a cesium response about 65 times the median of the other samples.

Why this matters

For any critical metal project, one of the first questions is which mineral holds the metals, because that determines how it can be concentrated and recovered. At Discovery, the answer is mica. Gallium is concentrated mainly in mica, and rubidium in mica and feldspar, so a single mica concentrate could potentially capture both metals.

This is the same mineral setting as NMX East, where the company has focused its work on recovering gallium and rubidium from mica. The company can therefore follow the same path at Discovery: produce a mica concentrate and then test it using the recovery approach developed for NMX East. Bench-scale flotation testing will determine whether a mica concentrate can be produced effectively from Discovery material.

The study also gives the company a clearer model for future exploration:

• Mica-rich, chemically evolved pegmatite-related rocks are priority targets for gallium and rubidium.
• Mineral content may provide a lower-cost way to screen historical drill core for rubidium before more expensive assays are completed.
• The beryllium and cesium responses give the company two new targets, with specific samples and rock types to follow up.

Additional upside: beryllium and cesium

Sample 2Y produced a beryllium response about 21 times the median response of the other samples. It comes from a different rock type than the pegmatites that carry most of the rubidium, which suggests a separate target on the property. Beryllium is a critical mineral used in aerospace, defence and electronics applications. The company will use certified assays and detailed mineral testing to confirm the result and identify the mineral that hosts it.

Sample 6Y produced a cesium response about 65 times the median response of the other eight samples. Mica content alone does not explain this difference, which suggests cesium may be concentrated in another mineral. Like beryllium, cesium is a critical mineral. It is used in the atomic clocks that support GPS and telecommunications networks and in high-density drilling fluids. The company will use certified assays and detailed mineral testing to confirm the result and identify the mineral that hosts the cesium.

Each of these findings is based on a single sample and has not yet been confirmed by certified assay. The results do not indicate the size or continuity of either target.

Certified gallium and rubidium results

The laser study shows where gallium and rubidium occur; certified assays show how much is present.

The 2018 drilling returned gallium above the detection limit in 194 one-metre core samples. Results ranged from 11 to 88 parts per million and averaged 37 parts per million. Seventy-two samples exceeded 40 parts per million, and 10 exceeded 50 parts per million.

Surface samples collected from 2022 to 2024 returned up to 59 parts per million gallium. Sodic pegmatite samples averaged 48.6 parts per million, compared with 20.5 parts per million for all other rock types sampled on the property.

The company also checked two previously reported drill intervals against the certified assay database:

• DE-DH-10, from 44.00 to 194.00 metres: 38.4 parts per million gallium and 694 parts per million rubidium across 83 one-metre samples; and
• DE-DH-06, from 9.00 to 39.00 metres: 37.0 parts per million gallium and 936 parts per million rubidium across 30 one-metre samples.

These averages agree with the results reported by the company on April 9, 2025. Parts per million and grams per tonne are equivalent measurements for these results.

Marcy Kiesman, chief executive officer of Quantum Critical Metals, commented: "These results are an important step for Discovery. The mapping shows that gallium and rubidium are held in mica, the same host mineral we are already working with at NMX East. That gives us a clear, practical path forward, because we know what to target and how we intend to test recovery. The beryllium and cesium responses were unexpected and are potential additional upsides, which we will now follow up with certified assays and mineral testing."

Next steps

The company plans to:

• Complete certified multielement assays on all nine samples;
• Carry out bench-scale flotation testing to produce a mica concentrate from Discovery material and test that concentrate using the recovery approach developed for NMX East;
• Use detailed mineral testing to identify the minerals hosting beryllium in sample 2Y and cesium in sample 6Y;
• Complete the historical depth records for six samples that have been linked to drill holes but not yet to exact intervals; and
• Test the relationship between mineral content and rubidium assay results on 30 to 50 samples before applying it more broadly.

Important technical context

The nine samples were selected from historical core and surface material to represent different rock types. They were not collected through a property-wide sampling program and represent only a very small portion of the 6,082-hectare project. The study therefore does not show property-wide grades, size or continuity. The beryllium and cesium responses each come from one sample and may not be confirmed by assay. Recovery work completed at NMX East may not be representative of Discovery material, and the results reported here do not demonstrate economic recovery. The work also does not support any conclusion, positive or negative, about the project's rare earth potential. Laser mineral mapping identifies minerals and element locations on prepared rock surfaces. It is not a certified grade assay. No mineral resource or mineral reserve is reported or implied.

Qualified person

The scientific and technical information in this news release has been reviewed and approved by George M. Yordanov, PGeo (OGQ No. 1612) of GMY Consulting Inc., an independent qualified person as defined under National Instrument 43-101.

Grant of stock options

The company also announces that it has granted an aggregate of 1.4 million incentive stock options to consultants under the company's stock option plan. Each option entitles the holder to purchase one common share of the company at an exercise price of 10 cents per share for a period of two years from the Sept. 28, 2026, grant date, expiring on Sept. 28, 2028. The options vest immediately and are subject to final acceptance by the TSX Venture Exchange.

About Quantum Critical Metals Corp.

Quantum Critical is focused on unlocking North American gallium and rubidium from mica, with silver exploration upside. The company is advancing a strategically located portfolio of critical mineral projects aimed at strengthening North American supply chains for next-generation technologies. Its flagship NMX East project is located in the Eeyou Istchee James Bay region of Quebec, near Nemaska Lithium's Whabouchi project and Power Metallic Mines Inc.'s Nisk-Lion-Tiger polymetallic discoveries. Quantum's portfolio includes gallium, rubidium, cesium, antimony, germanium, silver and other critical minerals across projects in Quebec and British Columbia. By combining high-potential mineral assets with innovative processing technologies, Quantum is positioning itself as an emerging North American source of the critical minerals required for semiconductors, aerospace, defence, advanced electronics and clean energy.

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