East Star Reso Regulatory News (EST)

8 October 2025

East Star Resources Plc

("East Star" or the "Company")

Epithermal Gold Exploration Update

Rock chips indicate fertile epithermal gold target at Snowy

East Star Resources Plc (LSE:EST), which is exploring for copper and gold in Kazakhstan, is pleased to provide an update on recent exploration activities and future work plans in relation to its Snowy epithermal gold target.

Highlights:

· Additional rock chip analysis and mapping highlight prospective vein system

· Vein samples show gold up to 1.44g/t at surface

· Veins traced over 100m of strike and continue open to the north

· Current interpretation fits with a low-sulphidation epithermal mineralisation model - geological similarities with: Round Mountain (20Moz Au, Kinross) and Silicon-Merlin (16Moz Au, AngloGold) in Nevada; Fruta-del-Norte (>14Moz Au, Lundin Gold) in Ecuador; and Pajingo (>3.5Moz Au, Yuxin Holdings) in Queensland

Alex Walker, East Star CEO, commented:

"The latest mapping and rock chip geochemistry is delivering encouraging results at Snowy. Recent field work by East Star's geological team has included several mapping and sampling transects over the Snowy alteration system with encouraging gold results at surface. We have updated our deposit model to a low-sulphidation epithermal system based on the geology observed at surface. This deposit type is characterised by geological similarities seen in notable deposits around the world, particularly in Nevada. We're excited to continue testing this new model, which has the potential to host a large gold system."

Copper Porphyry/Epithermal Gold

As East Star has increased its understanding of the alteration and surface expression of the anomaly, the Company's interpretation of the target has changed to focus on a low-sulphidation style of mineralisation.

The stratigraphy consists of a series of bedded volcaniclastic units, which dip moderately (between 30⁰ and 40⁰) to the north. All the rocks are pervasively silica and sericite altered at the surface. The auriferous veins cut the stratigraphy at a steep angle, which presents an attractive conceptual target at depth where there is the potential to find the 'boiling zone' where the ascending fluids meet with a more permeable - usually volcaniclastic - host rock, representing an attractive host rock for gold.

The Snowy veins are typically composed of quartz with minor occurrences of pyrite and the gold is associated with the veins at surface. The surface expression of these veins is between 15m and 30m wide and has been traced along strike for over 100m, east-west. The system dips steeply to the north (around 70⁰), cross-cutting the stratigraphy.

The Snowy alteration as observed in the hyperspectral data is characterised by a pyrophyllite anomaly at the western end (which was the initial focus of the exploration work) and then a high Al-OH sericite anomaly running along the northern strike of the ridge and a low Al-OH sericite anomaly running along the southern strike of the ridge which hosts the Eastern Target (See Figures 1 & 2). The current interpretation is that the variation between the high and low Al-OH sericite marks a stratigraphic contact between the volcaniclastic units.

Figure 1 - Schematic Section across Snowy Target showing selected mineralised rock chips

Note on Low-sulphidation Epithermal Mineralisation

East Star is now evaluating the potential for gold at Snowy using a low-sulphidation epithermal deposit model. Low-sulphidation epithermal gold deposits form in the near surface environment where hot ascending hydrothermal fluids mix with meteoric water, which cools the hydrothermal fluids and induces mineral precipitation. The fluids forming the deposit are typically neutral to mildly acidic and the alteration is typically less intense than high sulphidation systems; consisting mostly of adularia and sericite alteration. The spectral data demonstrates that the Snowy alteration system is mostly composed of sericite and is less intense than the nearby lithocap to the south-west of the Snowy target.

Snowy has numerous key features expected when targeting this deposit style:

1. Veining at surface - Quartz veins with gold and low base metal content at surface - see Figure 1

2. Alteration - Sericite alteration confirmed through TerraSpec and hyperspectral data

3. Permissive host rocks - tuffaceous and volcaniclastic rocks

4. Scale - demonstrated alteration over a very large area

The largest examples of low-sulphidation deposits in production are Round Mountain (20Moz Au) and Silicon-Merlin (16Moz Au) in Nevada.

Next Steps

Now that drilling has been concluded in the East Region, the Company's geologists will conduct a mapping and sampling programme over the veins at Snowy with the aim of collecting much closer spaced samples over the vein to establish the true scale of the mineralisation at surface and better delineate the target. Following this, an IP survey would be a likely next step to seek to illuminate the potential for mineralisation at depth below the surface anomaly in preparation for drilling.

Contacts:

East Star Resources Plc

Alex Walker, Chief Executive Officer

Tel: +44 (0)20 7390 0234 (via Vigo Consulting)

SI Capital (Corporate Broker)

Nick Emerson

Tel: +44 (0)1483 413 500

Vigo Consulting (Investor Relations)

Ben Simons / Peter Jacob / Anna Stacey

Tel: +44 (0)20 7390 0234

About East Star Resources Plc

East Star Resources is focused on the discovery and development of copper and gold in Kazakhstan. East Star's management are based permanently on the ground, supported by local expertise. The Company is pursuing multiple exploration strategies:

· Volcanogenic massive sulphide (VMS) exploration, which to date includes a deposit with a maiden JORC MRE of 20.3Mt @ 1.16% copper, 1.54% zinc and 0.27% lead, in an infrastructure-rich region, amenable to a low capex development

· Copper porphyry and epithermal gold exploration, with multiple opportunities for Tier 1 deposits, initially supported by an initial US$500k grant from BHP Xplor in 2024

Visit our website:

www.eaststarplc.com

Follow us on social media:

LinkedIn: https://www.linkedin.com/company/east-star-resources/

X: https://x.com/EastStar_PLC

Subscribe to our email alert service to be notified whenever East Star releases news:

www.eaststarplc.com/newsalerts

The person who arranged for the release of this announcement was Alex Walker, CEO of the Company.

Competent Person Statement

The technical information related to East Star Resources assets contained in this report that relates to Exploration Results is based on information compiled by Mr Christopher van Wijk, who is a Member of the Australasian Institute of Mining and Metallurgy and who is a Geologist employed by East Star Resources as an Executive Director. Mr van Wijk has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration, and to the activity which he is undertaking, to qualify as a Competent Person as defined in the 2012 Edition of the 'Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves'. Mr van Wijk consents to the inclusion in the release of the matters based on the information he has compiled in the form and context in which it appears.

This announcement contains inside information for the purposes of Article 7 of Regulation 2014/596/EU which is part of domestic UK law pursuant to the Market Abuse (Amendment) (EU Exit) Regulations (SI 2019/310) ("UK MAR"). Upon the publication of this announcement, this inside information (as defined in UK MAR) is now considered to be in the public domain.