Announcement PDF RNS Number : 4329V Altona Rare Earths PLC 15 August 2025 15 August 2025 ALTONA RARE EARTHS PLC ("Altona" or "the Company") MONTE MUAMBE: HIGH GALLIUM GRADE AND GALLIUM - FLUORSPAR ASSOCIATION CONFIRMED Altona Rare Earths PLC (LSE: REE), the resource exploration and development company advancing critical raw materials projects in Africa, is very pleased to announce that it has received from SGS Johannesburg partial mineralogy and geochemistry results of Monte Muambe gallium samples. Laboratory results on two fenite samples collected in June 2025 confirm previous gallium results obtained using the Company's pXRF analyser, with grades of 210 and 269 g/t respectively. In addition, mineralogy results identified the presence of fluorspar in both gallium-containing samples, with 34.00 and 26.38% Fluorite (equivalent to CaF2) respectively. The presence of fluorite had not been detected in the initial pXRF analyser assays because this device cannot analyse the chemical element fluorine. It is also very encouraging that the fluorite content of these samples is significantly above the cutoff grade intended for the resource estimate to be prepared later this year (cut-off grades ranging from 15% to 20% CaF2 will be tested). The Company will therefore consider these rocks as potential ore for the fluorspar project. In addition, the samples contain over 45% of K-feldspar, a mineral that previous metallurgical testing has shown can easily be separated from fluorite, auguring of enhanced recoveries for this type of ore. Mineralogical characterisation continues with the aim of confirming which mineral species contains gallium. Due to the chemical properties of this element, gallium is unlikely to be hosted in fluorite. During the flotation process, gallium concentration is therefore expected to increase in the tailings (the left-over materials) after fluorite is extracted. This may potentially enhance the economic and technical feasibility of recovering gallium from the flotation tailings. These results also provide additional validation of the use of gallium for fluorspar exploration, which resulted in the discovery of new fluorspar outcrops announced on 28 May 2025 (assay results announced on 7 July 2025), and further strengthens the Company's confidence in increasing the fluorspar resource base through additional surface exploration and drilling planned this quarter. Gallium is a rare metal usually extracted as a by-product from zinc and bauxite ore and is used in a wide range of electronic and high-technology applications such as radars, light diodes and semiconductors. Because of the superior performance of electronic components made with gallium, they are typically used in critically important military applications. Gallium is considered a strategic raw material by several jurisdictions including the European Union, with China having a quasi-monopoly on its production. China banned exports of gallium to the United States in December 2024, and this ban is still in place. Cedric Simonet, CEO of Altona, commented: "I am very excited to see that every fluorspar and gallium result coming back from the field and from the lab is serving to only strengthen further this project and its potential economics. I look forward to starting the resource drilling campaign during the course of this quarter and updating shareholders as this work progresses." This announcement contains information which, prior to its disclosure, was inside information as stipulated under Regulation 11 of the Market Abuse (Amendment) (EU Exit) Regulations 2019/310 (as amended). To subscribe for RNS alerts, please visit:https://investors.altonare.com/ -endsAltona Rare Earths Plc Cédric Simonet, CEO +44 (0) 7778 866 108 Louise Adrian, CFO +44 (0) 7721 492 922 Strand Hanson (Financial Adviser) +44 (0) 20 7409 3494 Christopher Raggett About Altona Rare Earths Plc Altona Rare Earths Plc (ticker: REE) is a London Main Market-listed exploration and development company focused on unlocking the value of critical raw materials across Africa. The Company is pursuing a diversified strategy, targeting assets with potential for near-term monetisation alongside long-term growth. The multi-commodity Monte Muambe Project in northwest Mozambique is a highly prospective tenement hosting rare earths, fluorspar, and gallium mineralisation. Since acquiring the project in June 2021, Altona has drilled over 7,800 metres, delivering a maiden JORC Mineral Resource Estimate of 13.6Mt at 2.42% TREO, secured a 25-year mining licence (granted December 2024), and published a Competent Person Report and scoping study for the rare earths component of the project (October 2023). The Company is actively seeking a strategic downstream rare earths partner to advance the project through the prefeasibility stage. In parallel, Altona is progressing plans to fast-track the development of high-grade fluorspar veins identified along the western and southern margins of Monte Muambe, with a targeted production of 50,000 tonnes per annum of acid-grade fluorspar over a minimum 12-year mine life. Acid-grade fluorspar is a key input in a wide range of applications, including hydrofluoric acid and lithium battery electrolyte production, placing Altona in a strong position to supply this critical material. The discovery of gallium mineralisation, with grades up to 550 g/t identified to date, adds further value to Monte Muambe. The Company is undertaking mineralogical and metallurgical studies to assess the potential for gallium production. Altona's diversified portfolio also includes the Sesana Copper-Silver Project in Botswana, strategically located just 25 km from MMG's Khoemacau Zone 5 copper-silver mine. Situated on a recognised regional contact zone for copper deposits, Sesana represents a compelling exploration opportunity aligned with Altona's growth strategy. With a unique combination of critical raw materials projects, Altona is well positioned to contribute to the global supply of highly sought commodities essential for clean energy, high technology, defence and industrial applications. The Company and the Board remain actively focused on identifying and evaluating additional projects that align with our investment profile and strategic objectives, leveraging our extensive network and combined industry experience to uncover compelling opportunities that can drive long-term growth. Competent Person Statement The information in this RNS that relates to geology and exploration results is based on information compiled and/or reviewed by Cédric Simonet, who is a Member of European Geologist Federation (Eur. Geol. #739). Cédric Simonet is the Chief Executive Officer and a Director of the Company. He has sufficient experience which is relevant to the styles of mineralisation and type of deposit under consideration and the activity which he is undertaking to qualify as a Competent Person in terms of the 2012 Edition of the Australian Code for the Reporting of Exploration Results, Mineral Resources and Ore Reserves. 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