Locksley Resources Ltd
Locksley Resources Strikes High-Grade Antimony at Depth, Validating a Potentially Larger Mineralised System at the Desert Antimony Mine
Locksley Resources (ASX: LKY) has delivered a compelling set of maiden drill results from its Desert Antimony Mine (DAM) in California, confirming that Locksley Resources high-grade antimony drill results at the Desert Antimony Mine California demonstrate that high-grade antimony mineralisation extends meaningfully below the historical underground workings. Six of eight completed diamond drill holes have returned significant antimony intersections, with assay results pointing to a structurally controlled hydrothermal system that may be considerably larger than previously understood.
The headline result — 0.4 metres grading 33.51% Sb within a broader interval of 4.0 metres at 4.87% Sb in hole DADD0005A — is among the highest-grade antimony intercepts reported from a first-pass drill program at this scale. Importantly, every drill hole in the program intersected antimony mineralisation below the historic mine workings, providing strong geological validation of the company's 3D modelling and depth-extension thesis.
These results come at a time when antimony has attracted substantial attention as a critical mineral, with Locksley actively pursuing a mine-to-market strategy for U.S. domestic antimony supply through its Mojave Project in San Bernardino County, California.
"Diamond drilling at the historic Desert Antimony Mine represents the first test of the depth extensions of known antimony mineralisation beneath the historical workings, with mineralised veins intersecting 90m below existing underground workings. The results are consistent with the observations from surface sampling and underground mapping and are continuing to be evaluated in the context of our evolving geological model."
— Ian Stockton, Non-Executive Technical Director, Locksley Resources
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What the Drill Results Actually Show
The maiden diamond drill campaign comprised eight holes totalling 1,065 metres, completed between February and April 2026. Assay results have been received for six holes, with the remaining two — DADD0006 and DADD0007 — still being processed at American Assay Laboratories (AAL) in Reno, Nevada.
All reported intersections are downhole widths; true widths are not yet determined.
Significant Intercepts Summary (≥0.5% Sb Cut-Off)
| Hole ID | From (m) | To (m) | Interval (m) | Sb (%) | Notable High-Grade Inclusion |
|---|---|---|---|---|---|
| DADD0001 | 70.95 | 71.45 | 0.5 | 2.76% | — |
| DADD0003 | 64.10 | 66.10 | 2.0 | 2.69% | 0.60m @ 6.66% Sb |
| DADD0003 | 56.00 | 56.90 | 0.9 | 1.88% | — |
| DADD0003 | 37.60 | 38.00 | 0.4 | 1.90% | — |
| DADD0004 | 41.70 | 43.10 | 1.4 | 5.62% | 0.40m @ 8.81% Sb |
| DADD0005 | 26.95 | 28.40 | 1.45 | 1.26% | 0.60m @ 1.98% Sb |
| DADD0005A | 32.70 | 36.70 | 4.0 | 4.87% | 0.40m @ 33.51% Sb |
| DADD0005A | 52.50 | 53.10 | 0.6 | 1.74% | 0.30m @ 2.82% Sb |
The stand-out interval from DADD0005A also contains a secondary high-grade inclusion of 0.40 metres at 8.24% Sb, reinforcing the internal richness of this particular vein zone.
Hole DADD0004 delivered two separate mineralised intervals — including 1.4 metres at 5.62% Sb with internal grades peaking at 8.81% Sb over 0.4 metres — furthermore confirming the multi-zone character of the system.
The Geology Behind the Numbers
Understanding why these results matter requires a brief look at what the drilling has revealed about the physical nature of the deposit.
Mineralisation at DAM is hosted in subvertical quartz-stibnite veins and associated vein breccias within granite gneiss and tonalite host rock. The style of mineralisation — particularly the vein breccia textures observed in hole DADD0004 — is characteristic of structurally controlled hydrothermal systems, where antimony-bearing fluids have migrated along fault pathways and precipitated as concentrated stibnite minerals.
A critical geological observation from the drilling is that antimony-rich veins appear to occur within a broader mineralised envelope rather than as isolated, narrow, laterally discontinuous structures. This is an important distinction: it suggests the mineralised system has width and continuity beyond what individual vein intercepts might imply, and it opens the door to a potentially larger resource than the historical mine footprint would suggest.
Mineralised veins have now been confirmed at depths of approximately 90 metres below the existing underground workings, and the company believes the current drilling may represent only limited testing of a broader system with additional potential along strike and at depth.
Understanding Antimony and Stibnite: What Investors Need to Know
What Is Antimony?
Antimony (Sb) is a silvery-white metallic element that serves as a critical mineral in numerous industrial applications. It is primarily extracted from stibnite ore and is classified as a strategic material by major economies due to its essential role in flame retardants, lead-acid batteries, semiconductors, and defence applications.
What Is Stibnite?
Stibnite (Sb₂S₃) is the primary ore mineral for antimony — a naturally occurring antimony sulphide that typically forms as grey, metallic, needle-like or bladed crystals within hydrothermal quartz veins. The exceptionally high-grade interval of 33.51% Sb reported from DADD0005A is associated with semi-massive to massive stibnite, meaning the mineral comprises a large proportion of the rock volume in that section of core.
Why Does Antimony Matter Strategically?
The U.S. currently relies heavily on imported antimony, making domestic supply development a strategic priority across industry and defence supply chains. Consequently, Locksley's mine-to-market strategy is designed to address this supply gap through integrated resource development and processing.
Key Technical Terms
| Term | Definition |
|---|---|
| Stibnite | The primary ore mineral of antimony; antimony sulphide (Sb₂S₃) |
| Hydrothermal | Relating to hot, mineral-rich fluids that circulate through rock fractures, depositing minerals as they cool |
| Vein breccia | A rock texture where fragmented host rock is cemented by mineralised vein material |
| Cut-off grade | The minimum grade (here 0.5% Sb) used to define a mineralised interval for reporting |
| Downhole width | The length of a mineralised interval as measured along the drill hole axis, which may differ from true width |
| HQ core | A standard diamond drill core size with a 63.5mm diameter bit — used here throughout the program |
A Two-Pronged Exploration Program: Antimony and Rare Earths
While the DAM drill results command immediate attention, Locksley's Mojave Project is advancing on two fronts simultaneously.
El Campo REE Prospect
Four diamond drill holes for 434 metres have been completed at the El Campo Rare Earth Element (REE) prospect. All geological logging is finished and core samples are currently being assayed at AAL. Results are expected within the coming weeks.
Ongoing ground-level work at El Campo includes:
- A ground radiometrics survey
- Geological field mapping
- Channel sampling of an interpreted carbonatite outcrop
Carbonatite-hosted REE deposits are among the highest-grade rare earth occurrences globally, and the thorium radiometric anomalies identified at El Campo — visible in the reimaged geophysical data — provide important geological context for the drilling program.
Regional Exploration
Beyond the two drill prospects, Locksley has commenced regional targeting across the broader Mojave Project. Enhanced reimaging of the thorium radiometric dataset — acquired in late 2025 — has revealed several new, high-priority anomalies in the northwestern area of the Northern tenement block after removing the overwhelming signal from the Mountain Pass mine waste. These anomalies are now under active investigation.
In addition, the company is re-assaying previous stream sediment pulps for a wider range of elements, including antimony, to assist with regional targeting.
What Comes Next: Catalysts on the Horizon
Locksley has outlined a clear set of near-term activities that will drive news flow and advance the geological understanding of both prospects.
| Activity | Timing | Significance |
|---|---|---|
| Remaining DAM assay results (DADD0006, DADD0007) | Shortly | Completes the maiden drill dataset |
| El Campo REE assay results | Coming weeks | First drill-based REE data for the prospect |
| Updated 3D geological model for DAM | Following receipt of all results | Underpins targeting for follow-up drilling |
| Structural interpretation and geometry review at DAM | Ongoing | Assesses strike and depth extension potential |
| Metallurgical and mineralogical assessment | Planned | Critical step towards understanding processing requirements |
| Ground radiometric surveys and rock chip sampling | Ongoing | Tests priority regional anomalies across Mojave Project |
The pending results from DADD0006 and DADD0007 — both drilled to test different orientations and positions relative to the known mineralisation — will complete the picture from the maiden program. Together with the El Campo results, the next two to four weeks could see a material uplift in the geological dataset underpinning the Mojave Project.
The Investment Case: Why This Program Matters
The maiden drill program at DAM has achieved something that carries genuine significance for the investment thesis: it has independently confirmed, through laboratory-verified diamond drilling, that a high-grade antimony system exists at depth beneath a historically productive mine.
Several points reinforce the investment relevance of these results:
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Geological validation of the model. Drilling was designed to test the depth extension of known surface and underground mineralisation. Every hole hit antimony — this is not a selective outcome but a consistent result across the full program, supporting the geological model.
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Grade quality is exceptional. A peak value of 33.51% Sb over 0.4 metres is very high for antimony drilling. Historical production grades from the DAM are noted at 15–20% Sb, and the best drill intercepts are meeting or exceeding that benchmark.
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System scale remains open. The company's own assessment is that current drilling represents limited testing of what may be a broader hydrothermal system. Strike extensions to the north and south, as well as down-dip continuity, remain untested — providing a clear runway for follow-up programs.
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Dual commodity exposure. While DAM provides the antimony narrative, the concurrent El Campo REE drilling adds a second potential value driver. Pending assay results from both programs mean multiple news catalysts are expected in the near term.
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Mine-to-market strategy. Locksley is not solely a resource explorer. The company describes an integrated approach combining resource development with processing and separation technologies, targeting U.S. domestic antimony supply chains. If resource definition progresses, the pathway from drill results to potential production has strategic downstream underpinning.
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Why Investors Should Keep Watching Locksley Resources
Locksley has executed a well-designed maiden drill program at a historically significant antimony mine and returned results that meaningfully advance the geological case for a larger system. The company is now in an active news flow period, with assay results from two additional DAM holes and four El Campo REE holes all pending in the near term.
The combination of Locksley Resources high-grade antimony drill results at the Desert Antimony Mine California, an emerging REE prospect in a prospective geological setting adjacent to Mountain Pass, and an active regional exploration program across a ~40 km² project area gives the company multiple avenues through which to build value.
- Remaining drill assays arriving shortly could expand or further define the known mineralised footprint
- El Campo REE results will provide the first drill-based test of the carbonatite-hosted REE interpretation
- Metallurgical work, when initiated, will begin to frame the processing story critical to any mine-to-market pathway
- Regional anomaly follow-up could identify entirely new targets within the Mojave Project
Locksley Resources has confirmed high-grade antimony mineralisation at depth below the historic Desert Antimony Mine, with a peak grade of 33.51% Sb and multiple significant intersections across six drill holes. With a potentially larger hydrothermal system open along strike and at depth, pending REE assays from El Campo, and active regional exploration underway, the Mojave Project is entering a period of accelerating news flow that investors in the critical minerals space should be monitoring closely.
Want to Know More About Locksley Resources and the Mojave Project?
With high-grade antimony confirmed at depth beneath the Desert Antimony Mine, pending assay results from both the remaining DAM holes and the El Campo REE prospect, and a mine-to-market strategy targeting U.S. domestic critical mineral supply chains, Locksley Resources is entering a period of significant news flow. Investors looking to understand the full scope of the Mojave Project — from the antimony drilling program through to the emerging REE prospect and regional exploration pipeline — can find further details, ASX announcements, and company updates at locksleyresources.com.au.
