Mineral Mapping at Discovery Property Confirms Mica as Host for Gallium and Rubidium, Enhancing Recovery Path

Vancouver, British Columbia — September 29, 2026 — Leads & Copy — Quantum Critical Metals Corp. has reported advanced laser mineral mapping results from nine historical samples from its wholly owned Discovery Property in Québec's Eeyou Istchee James Bay region. The findings indicate that gallium and rubidium at the Discovery Property are primarily held within mica, the same host mineral the Company is currently working with at its flagship NMX East Project.

This discovery allows Quantum to leverage its existing expertise in gallium and rubidium recovery from mica at NMX East, applying it directly to the Discovery Property without needing to develop a new approach. The study also revealed significant beryllium and cesium responses in two separate samples, identified as potential additional upsides for further investigation.

Key highlights from the report include the confirmation that gallium is hosted in mica, as it was detected in all nine samples, with eight showing a strong correlation between the gallium response and the amount of mica present. Rubidium was found to be hosted in both mica and feldspar, closely tracking the combined quantity of potassium-bearing mica and feldspar, evidenced by a high statistical relationship (R² of 0.988). The identification of mica as the primary host mineral at Discovery, mirroring that of NMX East, simplifies the recovery strategy.

Furthermore, the mapping identified a new beryllium target, with one sample showing a response approximately 21 times the median of other samples, originating from a rock type distinct from the rubidium-bearing pegmatites. A separate sample yielded a cesium response about 65 times the median, indicating another potential target. Beryllium is a critical mineral utilized in aerospace, defense, and electronics, while cesium plays a crucial role in atomic clocks for GPS and telecommunications, as well as in high-density drilling fluids.

The Company intends to follow up on these findings with certified assays and detailed mineral testing to confirm the results and identify the specific minerals hosting beryllium and cesium. It is important to note that these beryllium and cesium findings are based on single samples and have not yet been confirmed by certified assay, and do not indicate the size or continuity of these potential targets.

Certified assays from previous drilling and surface sampling also provide context. In 2018, drilling returned gallium above the detection limit in 194 one-metre core samples, with an average of 37 parts per million. Surface samples collected between 2022 and 2024 showed up to 59 parts per million gallium, with sodic pegmatite samples averaging 48.6 parts per million. Two previously reported drill intervals also showed significant gallium and rubidium values.

Marcy Kiesman, CEO of Quantum Critical Metals, stated, “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.”

Quantum Critical Metals Corp. is focused on unlocking North American gallium and rubidium from mica, with potential silver exploration upside. The Company is advancing a portfolio of critical mineral projects aimed at strengthening North American supply chains. Its NMX East Project is in Québec, near other significant mineral discoveries.

Source: Quantum Critical Metals Corp.