Announcement • May 22
East Star Resources Plc Identifies Large Copper-Gold Target At Piket Project East Star Resources Plc announced the first results from exploration at the Company's Piket Licence which was awarded in 2025. Recent geological mapping, hyperspectral interpretation and geochemical sampling have identified a large and geochemically anomalous lithocap as a potential host for a copper-gold porphyry or epithermal system. The work has significantly enhanced the Company's understanding of the regional geological setting and identified one large priority target for follow-up exploration at the Symbyl 2 Prospect area. Recognition of a large-scale alkaline intrusive system geologically similar to the Macquarie Arc in Australia and younger alkalic porphyry systems in British Columbia, Canada. Extensive advanced argillic alteration system defined over an area of 8km x 3km. Soil sampling has outlined a 2km x 2km multi-element anomaly at the Symbyl 2 Prospect with coherent Au-Mo-Bi-Sn-W anomalism and gold values up to 0.2g/t Au. The Symbyl 2 Prospect identified as the priority target with intense quartz-pyrophyllite-alunite alteration and evidence of oxidised sulphides and porphyry-style "A" veins. Low sulfidation epithermal Au-Ag veins identified approximately 5km east of the main alteration corridor, confirming district-scale fertility and preservation of the epithermal environment. Next steps to advance Symbyl 2 to include detailed mapping and systematic sampling of historic trench material and additional rock chip sampling over defined anomalies. Recent geological interpretation has recognised an alkaline intrusive suite at Piket with geological characteristics comparable to major alkalic copper-gold porphyry districts, including the Macquarie Arc in New South Wales and younger alkalic porphyry systems in British Columbia, Canada. Field mapping confirmed the presence of classic alkalic alteration assemblages within monzonitic intrusions, including hematite-dusted potassium feldspar alteration ("Red Rock Alteration") and epidote-chlorite alteration associated with hornblende-bearing intrusive rocks. The recognition of this geological setting substantially increases the prospectivity of the broader project area for both porphyry copper-gold mineralisation and associated epithermal gold-silver systems. Furthermore, the Company believes that the regional potential for additional alkalic-related porphyry and epithermal systems remains underexplored and warrants broader scale regional targeting. Exploration at Piket has defined a large advanced argillic alteration ("AAA") system extending approximately 8km in strike length and 3km in width. The Piket Trend is dominated by lithocap-related alteration facies, interpreted to represent the upper portions of a large hydrothermal system. Ground validation work confirmed the quality and reliability of the satellite hyperspectral products, which were used extensively to map alteration mineralogy across the project. Interpretation of alteration zonation and geology suggests that the deeper portions of the hydrothermal system may be exposed in the southern portion of the corridor, particularly around the Symbyl 2 Prospect. This may reflect structural tilting or block faulting along the interpreted Piket Fault. The Symbyl 2 prospect has emerged as the highest priority target within the project area. Mapping identified extensive zones of intense advanced argillic alteration characterised by a quartz-pyrophyllite-alunite assemblage, hematite-bearing fractures and veins, and evidence of ex-sulphide textures. Importantly, minor porphyry-style quartz "A" veins were identified within the lithocap alteration assemblage, suggesting some degree of telescoping between porphyry and epithermal environments. Propylitic alteration within the surrounding host monzonite increases toward the Symbyl 2 lithocap, with increasing hematite dusting of feldspars and epidote-chlorite alteration of hornblende-bearing lithologies. The combination of alteration intensity, structural preparation, pathfinder geochemistry and porphyry-style veining indicates Symbyl 2 represents the most compelling target for a concealed copper-gold porphyry system. Soil sampling conducted at the end of 2025 has further strengthened the prospectivity of the Symbyl 2 target area. Sampling defined a coherent 2km x 2km geochemical anomaly with elevated gold values of up to 0.2g/t Au as well as multiple pathfinder elements commonly associated with fertile porphyry systems, including molybdenum (Mo), bismuth (Bi) tin (Sn) and tungsten (W), all of which are high level indicators of fertile porphyry systems, commonly found in lithocaps above porphyry systems. Gold anomalism appears spatially associated with the southern portion of the system and is concentrated within drainage systems adjacent to the lithocap. Molybdenum anomalism greater than 5ppm is preserved throughout multiple intervals of the lithocap system, further supporting the interpretation of a fertile hydrothermal environment. Field mapping also identified a series of low sulphidation epithermal ("LSE") gold-sliver veins approximately 5km east of the main Piket alteration corridor. The vein field, which was explored in soviet times, extends over approximately 1.5km x 1.5km and comprises multiple thin gold-silver bearing veins, which are themselves not considered economic but provide an important proof of fertility. The preservation of low sulphidation epithermal mineralisation confirms that the district has undergone fertile gold-bearing hydrothermal activity and retains preserved upper epithermal levels. This significantly enhances the potential for concealed porphyry systems elsewhere within the broader project area. Announcement • May 21
East Star Resources Plc, Annual General Meeting, Jun 15, 2026 East Star Resources Plc, Annual General Meeting, Jun 15, 2026. Location: the offices of orana corporate llp, eccleston yards, 25 eccleston place, sw1w 9nf, london United Kingdom Announcement • May 14
East Star Resources plc Announces Appointment of Sonia Scarselli as Director, Effective May 13, 2026 East Star Resources Plc announced the appointment of Sonia Scarselli as a Director of the Company with immediate effect on May 13, 2026. Ms Scarselli has been appointed as a director representative of Endeavour Mining PLC following Endeavour's strategic investment in East Star, announced on December 1, 2025, which resulted in Endeavour owning 14.3% of the Company. Ms Scarselli joined Endeavour in 2025 as Executive Vice President, Exploration. Prior to Endeavour, Ms Scarselli was VP of BHP Exploration and founded BHP's Xplor programme (East Star: 2024 cohort) in 2022. Ms Scarselli started her career at ExxonMobil UK and later joined BHP in 2012, holding several leadership positions including VP of Petroleum Exploration and Appraisals, Head of Algeria, and Exploration Manager for Trinidad and Tobago. Ms Scarselli holds a master's degree in Geological Science from Università degli studi di Perugia, a PhD in Geology from ETH Zurich, and an MBA from the London Business School. She was appointed a Director of Koulou Gold Corp. in March 2026. In November 2025, East Star and Endeavour formed a strategic joint venture agreement for gold exploration in Kazakhstan, followed in November 2025 by Endeavour's £1.8 million strategic investment in East Star. 
