Hillgrove Confirms High-Grade Copper at Emily Star
Hillgrove Resources has delivered consistent high-grade copper-gold drill results from its Emily Star underground project, underpinning a pivotal Stage 2 investment decision later this year.
- Seven drill holes completed with five assay results received
- High-grade copper-gold intersections align with 2024 resource estimates
- Drilling supports geological and geotechnical confidence for expansion
- Stage 2 final investment decision expected in second half of 2026
- 2026 Mineral Resource update scheduled for December quarter
Emily Star Drilling Confirms Robust High-Grade Zones
Hillgrove Resources (ASX:HGO) has reported encouraging underground drilling results from the Emily Star deposit at its Kanmantoo Copper Mine in South Australia. Since early April 2026, seven drill holes have been completed from a newly established underground platform, with assay results for five holes confirming consistent high-grade copper-gold mineralisation. The standout intercepts include 19 metres at 1.49% copper and 0.13 grams per tonne gold, and 15.87 metres at 1.53% copper and 0.21 grams per tonne gold, both from significant depths around 250-290 metres downhole.
These results broadly align with the 2024 Mineral Resource Estimate (MRE) for Emily Star, which was based on earlier surface drilling. The underground drilling’s improved orientation has refined understanding of mineralisation geometry and structural controls, revealing variations in lode width and grade that will inform mine planning.
Advancing Towards Stage 2 Investment Decision
CEO Bob Fulker emphasised that the drilling campaign is providing the geological and geotechnical confidence necessary to support the Stage 2 final investment decision (FID), expected in the second half of 2026. While initial results are promising, Hillgrove is continuing detailed design and economic assessments before committing to the Emily Star expansion.
Ongoing studies include geotechnical evaluations, ventilation design, mine infrastructure, and mine planning. The combination of strong operational performance and progress across growth initiatives positions Hillgrove well for this next phase of value creation.
Drilling Program and Resource Update Timeline
The underground diamond drilling program has logged over 25,700 metres year-to-date, including 2,800 metres at Emily Star. Drilling will continue through the September quarter to further delineate mineralisation and support mine planning. Pending assay results from some intervals and geotechnical testing remain, with unsampled sections assumed as zero copper for current assessments.
All drilling results will feed into the 2026 Mineral Resource update, scheduled for release in the December quarter. This update will be critical in refining resource estimates and underpinning the economics of the Emily Star underground project.
Strategic Positioning in South Australian Copper Market
Hillgrove’s drilling progress at Emily Star complements its broader growth strategy, which includes ramping up production at Kanmantoo and advancing the Mutooroo farm-in deal. The company’s focus on expanding high-grade underground resources aligns with tightening global copper supply dynamics and rising demand.
Bottom Line?
Emily Star’s drilling results reinforce its potential as a cornerstone for Hillgrove’s underground expansion, but key economic studies and resource updates in the coming months will be decisive.
Questions in the middle?
- How will the pending geotechnical results influence mine design and capital expenditure?
- What are the key economic thresholds Hillgrove is targeting for the Stage 2 investment decision?
- Could further drilling extend the Critchley lode’s known boundaries and add to the resource base?
