Berkeley Energia Unveils First Lithium and Rubidium Resource Estimate at Spain’s Conchas Project

Berkeley Energia’s Critical Minerals Focus in the Iberian Peninsula

Berkeley Energia Limited, an ASX-listed minerals explorer, focuses on critical materials within Spain. The Conchas Investigation Permit covers 31 square kilometres in southwestern Salamanca province, near the Portuguese border in Espeja and Fuentes de O f1oro municipalities. Situated roughly 21 kilometres from Ciudad Rodrigo and 110 kilometres from Salamanca city, the project benefits from established road access. This location lies within the Central Iberian Zone, a geologically significant area renowned for lithium mineralisation potential.

The company’s Critical Minerals Exploration Initiative strategically targets elements vital for modern technology and defence. Lithium is designated by the European Union as a Critical and Strategic Material due to its essential role in battery technology supporting decarbonisation, energy security, and industrial competitiveness. Rubidium, the secondary commodity at Conchas, holds equal strategic importance, recognized as a critical mineral by the United States, Japan, and New Zealand because of its applications in defence, aerospace, communications, medical technology, and renewable energy. Berkeley Energia’s dual-commodity approach positions it to capitalize on both immediate energy transition demand and long-term strategic technology needs.

Maiden Resource Estimate Highlights Shallow, Bulk-Tonnage Potential at Conchas

The maiden Mineral Resource Estimate for Conchas totals 11.8 million tonnes averaging 0.41% lithium oxide and 0.21% rubidium oxide, containing about 49,000 tonnes of lithium oxide and 25,200 tonnes of rubidium oxide. The estimate uses a net smelter return cut-off of US$100 per tonne and is constrained by an open-pit Whittle optimisation pit shell incorporating realistic mining, processing costs, recovery rates, and metal concentrate payability. The entire resource is classified as Inferred Mineral Resource, reflecting the current geological data and understanding. Mineralisation starts at surface and remains open at depth, indicating potential for resource expansion through ongoing exploration.

The shallow, bulk-tonnage nature of the deposit makes it well-suited for conventional open-pit mining, reducing capital and operational complexity compared to underground methods and potentially improving project economics. The mineralisation is hosted within a muscovite-rich leucogranite unit on the eastern edge of the Guarda granitic batholith. This Mineralised Muscovitic Leucogranite consistently contains economic minerals including rubidium, lithium, caesium, beryllium, tantalum, tin, and niobium, adding potential value to future processing.

Metallurgical Testing Validates Flotation and Magnetic Separation Techniques

Initial metallurgical testing confirms effective extraction of lithium and rubidium from Conchas mineralisation using conventional beneficiation methods. Flotation and magnetic separation delivered very good recoveries, demonstrating a viable pathway for commercial mineral processing. Flotation leverages mineral surface properties, while magnetic separation exploits magnetic characteristics to concentrate target minerals. These results indicate no need for unconventional processing technologies.

The grades achieved meet commercial specifications, especially important for rubidium, which commands premium prices due to limited supply and high-tech uses. Berkeley Energia plans a second metallurgical test phase to optimize flotation and magnetic separation, aiming to improve recoveries, lower processing costs, and refine product quality. Such optimisation precedes detailed engineering and feasibility studies essential for investment decisions.

Rubidium’s Strategic Role as a High-Value Critical Mineral

Rubidium holds a unique critical materials status due to its specialized applications and limited global supply. The Conchas Project hosts a globally significant rubidium oxide resource, with approximately 25,200 tonnes of contained Rb2O. Rubidium is used extensively in defence, aerospace, communications, medical devices, and renewable energy. The United States, Japan, and New Zealand classify rubidium as critical, reflecting supply security concerns. The European Union and Canada also recognize its strategic importance, driving demand for reliable sources beyond current dominant producers.

Conchas’s rubidium concentration, combined with Europe’s strategic supply chain focus, positions it as a potentially vital source for European and allied security interests. Unlike lithium, rubidium supply chains are less developed and more geographically concentrated, providing producers with pricing power and reduced commercial risk. The dual lithium-rubidium commodity profile at Conchas offers operational efficiencies and risk mitigation compared to single-commodity projects, making Berkeley Energia’s success noteworthy for strategic investors and governments prioritizing critical mineral security.

Geological Setting and Mineralisation in the Central Iberian Zone

Located within the Central Iberian Zone, one of the Iberian Peninsula’s most extensive geological formations, Conchas benefits from a 500-kilometre belt of lithium mineralisation trending north-northwest to south-southeast. Mineralisation styles vary, with Conchas hosted in peraluminous granites and muscovite-rich leucogranite, representing highly evolved magmatic fractionation stages. Such granitic systems are globally recognized as prime targets for lithium, caesium, and tantalum (LCT-style pegmatites). Geological indicators include evolved peraluminous granites, albite- and muscovite-rich assemblages, lithium-bearing phosphates and silicates, and enrichment in incompatible elements.

Six lithologies have been identified within the deposit area, with the Mineralised Muscovitic Leucogranite hosting economic elements. Other lithologies include two types of Biotitic Porphyritic Granite (coarse and fine regional), Muscovitic Granite, Fine Grain Cupuliform Granite, and Quartz Dykes. Core analyses reveal diverse mineralogy, including fine muscovite flakes, dark micas, and cassiterite. This complexity requires advanced geological modelling to accurately define mineral boundaries and grade continuity.

Resource Classification and Compliance with JORC Code Standards

The maiden Mineral Resource Estimate was prepared by independent consultants Maja Mining Limited and complies with the JORC Code (2012 Edition), the global standard for mineral resource reporting. The entire 11.8 million tonne resource is classified as Inferred Mineral Resource, reflecting current data density and geological confidence. Inferred classification requires reasonable geological continuity but less data than Indicated or Measured categories. Further data collection is necessary to upgrade resource confidence.

Berkeley Energia plans infill drilling to advance resource classification, consistent with industry norms. Progression to Indicated and Measured categories involves closer drill spacing and improved geological understanding. The US$100 per tonne net smelter return cut-off excludes uneconomic material, while the Whittle optimisation pit shell ensures realistic open-pit mining parameters. This rigorous approach enhances credibility and establishes a baseline for future updates.

Advancing Project Development with Infill Drilling and Metallurgical Work

Berkeley Energia intends to advance Conchas by conducting infill drilling aimed at upgrading resource classification from Inferred to Indicated and potentially Measured. This targeted drilling reduces data spacing, increasing confidence in grade and tonnage estimates, and supports feasibility studies and development decisions. Executive Director Robert Behets emphasized management’s confidence and commitment to systematic de-risking.

Simultaneously, a second metallurgical test phase will optimize flotation and magnetic separation processes, examining variables such as grind size, reagent dosage, flotation time, and separation parameters to maximize metal recovery and reduce costs. While specific timelines and budgets remain undisclosed, these programs are critical for improving project economics. Investors should monitor future updates on drilling results, metallurgical progress, and resource revisions.

Global Market Context and Demand Drivers for Lithium and Rubidium

This announcement occurs amid heightened global focus on critical mineral supply chains. Lithium demand is surging due to battery production for electric vehicles, grid storage, and electronics. The EU’s designation of lithium as Critical and Strategic Material reflects its vital role in decarbonisation, energy security, and industrial competitiveness. Governments are prioritizing supply chain resilience by fostering domestic and allied lithium sources, creating favorable conditions for new projects like Conchas.

Rubidium’s market differs but remains supportive. Historically limited and by-product sourced, rubidium’s critical mineral status in major economies reflects growing demand in defence, aerospace, communications, medical, and renewable energy sectors. The scarcity of large, economically viable rubidium deposits enhances Conchas’s strategic value. Nonetheless, commodity markets are volatile, and factors such as price fluctuations and competitive supply dynamics can impact project viability.

Project Location and Infrastructure Advantages for Development

The Conchas Investigation Permit covers 31 square kilometres in southwestern Salamanca, Spain, within Espeja and Fuentes de O f1oro municipalities. Proximity to established roads—21 kilometres from Ciudad Rodrigo and 110 kilometres from Salamanca—provides logistical benefits for exploration and potential mining. Access to transportation networks reduces infrastructure costs and facilitates connectivity to processing facilities, ports, and export routes. Spain’s regulatory environment offers clarity and stability compared to higher-risk jurisdictions.

Located near Portugal and integrated into the Iberian mining ecosystem, Conchas benefits from established mining heritage and infrastructure. Its distance from major population centers may ease community engagement challenges. However, future development will require mining concessions, environmental assessments, and stakeholder consultations. The company has not disclosed permitting status or timelines. Investors should watch for updates on regulatory progress, a critical step toward feasibility and development decisions.