Sunstone Metals advances partnership talks amid strategic focus on El Palmar and Bramaderos assets

Sunstone Metals Ltd made further progress in the March 2025 quarter on several corporate initiatives aimed at unlocking value from its major Ecuadorian gold-copper projects. Partnership discussions are ongoing with multiple parties, alongside key advancements at the El Palmar and Bramaderos projects.

During the quarter, Sunstone raised A$4 million via an institutional placement, with A$0.7 million received by March 31, 2025. Unaudited cash at quarter-end stood at A$0.9 million, with tradeable equity holdings valued at A$0.1 million.

Exploration expenditure for the quarter was A$1.5 million, while corporate and administrative outflows declined 24% from the previous quarter to A$0.5 million.

Partnership and transaction progress

Sunstone continued due diligence discussions with multiple counterparties regarding potential corporate-level and project-level transactions. Further site visits to the El Palmar and Bramaderos Projects are scheduled for the June quarter.

The company reported that an attractive opportunity has progressed to a stage where a non-binding indicative offer could be finalised in the short term. Separately, Sunstone is engaged in talks involving a potential combination with a private, nearer-term gold development asset, which could complement its two existing large-scale projects.

While additional parties have signed confidentiality agreements and shown interest, Sunstone has cautioned that there is no guarantee any transactions will proceed.

El Palmar Project – Northern Ecuador

Sunstone holds a 74.5% interest in El Palmar and can increase this to 100% by 30 June 2026. The maiden Mineral Resource Estimate (MRE) for the outcropping T1 porphyry stands at:

• 64 million tonnes at 0.60 grams per tonne gold equivalent (AuEq), containing 1.2 million ounces AuEq.

The MRE is based on 21 drill holes for 17,699m of drilling (18 drilled by Sunstone in the period August 2021 to July 2022 and 3 drilled by Codelco in 2012) and 1,498 linear metres of trenching in 5 trenches.

Additionally, an Exploration Target of 1.0–1.2 billion tonnes at 0.3–0.7 g/t gold and 0.1–0.3% copper outlines a conceptual potential of 10–27 million ounces gold and 1.0–3.7 million tonnes copper. This only includes three of the five identified porphyry targets, leaving scope for future growth.

Verde Chico Project

Verde Chico, adjacent to El Palmar, is currently under a staged acquisition agreement. Initial exploration activities have included rock chip and sediment sampling, with further geological mapping underway.

Location of the El Palmar and Verde Chico projects relative to the giant Llurimagua, Alpala and Tandayama- America (Cascabel project) porphyry deposits, and the Toachi fault system. Also shown are the concessions held by ENAMI that surround Llurimagua, and which Hanrine (subsidiary of Hancock Prospecting) have committed to spend US$120 million to earn 49%.

Bramaderos Project – Southern Ecuador

At Bramaderos, where Sunstone holds 87.5%, the Brama-Alba deposit hosts an MRE of:

• 156 million tonnes at 0.53 g/t AuEq, for 2.7 million ounces AuEq.

Bramaderos gold in soil contours showing the main porphyry and epithermal domains.

The broader Bramaderos concession features a porphyry Exploration Target of 3.3–8.6 million ounces AuEq, and the nearby Limon gold-silver epithermal target contains an additional 0.9–1.7 million ounces AuEq.

The Limon epithermal gold-silver system in plan view, showing multiple mineralised structures in green. High-grade domains are at intersections of NE and WNW trending structures. Recent intersections in holes LMDD048-051 extend mineralisation on the western and eastern sides of the Limon epithermal system. Several additional targets have been defined based on gold-in soil and zinc-in-soil anomalies, and structural interpretation.

Exploration at the Copete discovery has extended the mineralised corridor, with trenching results supporting a significant porphyry cluster extending 1.8 kilometres. 

The Copete target remains largely under-explored, with no drilling undertaken by Sunstone to date. However, recent trenching has confirmed a broad and coherent zone of gold-copper mineralisation. This is supported by a 3D-modelled magnetic anomaly plunging southeast—similar in character to that observed at Brama—and mapped stockwork veining interpreted as the upper expression of an intact porphyry system.