Lion Rock Minerals Hits 4.54% Rare Earths From Surface With Depth Still Untested
Key Takeaways
- Hole MRAU0238 returned 2.3m at 4.54% TREO from surface, with a peak single-sample grade of 21.15% TREO in the saprolite layer — auger drilling hit refusal before the mineralisation ended, signalling untested depth potential.
- The basket composition skews towards magnet-critical rare earths, with NdPr accounting for 21–24% of TREO across reported intervals and DyTb contributing 0.6–1.6%, both essential to EV motors and wind turbines.
- Every rare earth element assayed, plus scandium, appears on the 2025 U.S. List of Critical Minerals, adding geopolitical weight to the mineralisation profile.
- Grade consistency across the dataset is notable: 8 of 15 continuously assayed holes average more than 1.0% TREO on a zero-cut-off whole-hole basis, and 14 of 15 average at least 0.5% TREO.
- A 761-hole, 3,485m alluvial campaign completed 29 August 2026 generated 3,666 samples now entering the assay queue in batches — the first 638 samples are already at the laboratory, with results to flow over coming weeks.
High-grade rare earths confirmed from surface at Minta Est
Lion Rock Minerals (ASX: LRM) has released its first laboratory rare earth assays from Minta Est, confirming high-grade, monazite-hosted rare earth element (REE) and rutile mineralisation starting at surface and remaining open at depth.
The headline intercepts are striking. Hole MRAU0238 returned 2.3m at 4.54% Total Rare Earth Oxides (TREO) from surface, MRAU0239 delivered 3.0m at 3.40% TREO from surface, and MRAU0247 returned 2.0m at 3.49% TREO from surface, with each interval ending in mineralisation. Further intervals include 5.0m at 1.67% TREO and 5.6m at 1.14% TREO, both from surface and both ending in mineralisation.
The peak single-sample grade of 21.15% TREO was hit in the saprolite layer of MRAU0238, specifically the 2.0–2.3m interval. Auger drilling was unable to penetrate further into the saprolite, and the company is expediting diamond drill mobilisation to test the depth extent of this zone.
All reported grades are in-situ grades, not concentrate grades. Mineralisation is hosted in monazite, a well-understood REE-bearing phosphate mineral, alongside rutile. The Minta Rare Earth and Rutile Project covers an 8,800 km² province in Cameroon, Central Africa.
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What the basket composition means for investors
A high TREO number is only half the story. What sits inside that grade, the basket composition, determines commercial value, and Minta Est’s basket skews towards the minerals that matter most to clean energy supply chains.
The basket is magnet-rich, meaning it is weighted towards the rare earths that drive permanent magnets used in electric vehicle motors and wind turbines. Neodymium-praseodymium (NdPr) accounts for 21–24% of TREO across each reported interval. Dysprosium-terbium (DyTb) contributes 0.6–1.6% of TREO. While that DyTb percentage looks modest, its strategic significance is disproportionate: supply is heavily concentrated in China, and these heavy rare earths are what allow magnets to maintain their strength at the high operating temperatures found in EV motors and wind turbines.
Every rare earth element assayed by the ICP-OES programme, together with scandium, appears on the 2025 U.S. List of Critical Minerals, adding a layer of geopolitical relevance to the mineralisation.
What is TREO and why does basket composition matter?
TREO stands for Total Rare Earth Oxides. It is the standard grade measure for rare earth projects, expressed as a percentage, representing the combined concentration of all rare earth oxide species in the rock.
The critical point: TREO alone does not determine a project’s commercial value. A high TREO grade dominated by cerium or lanthanum, which are abundant and lower-value rare earths, is worth considerably less than a moderate TREO grade rich in NdPr and DyTb. The magnet basket, NdPr and DyTb specifically, commands the attention of EV and wind turbine supply chains because those elements cannot easily be substituted in permanent magnet applications.
The following table shows the top critical minerals from the leading 2.3m MRAU0238 interval, sourced directly from Table 3 of the announcement.
| Critical Mineral | Oxide Reported | 2.3m Interval Grade (%) | Strategic Use |
|---|---|---|---|
| Cerium | CeO₂ | 2.070% | Catalysts, polishing compounds and specialty alloys |
| Lanthanum | La₂O₃ | 0.987% | Batteries, catalysts and optical glass |
| Neodymium | Nd₂O₃ | 0.831% | High-strength permanent magnets |
| Praseodymium | Pr₆O₁₁ | 0.257% | Permanent magnets and aerospace alloys |
| Yttrium | Y₂O₃* | 0.240% | High-temperature ceramics, phosphors and specialty alloys |
| Samarium | Sm₂O₃ | 0.160% | High-temperature SmCo magnets and nuclear applications |
| Gadolinium | Gd₂O₃ | 0.103% | Specialty magnets, medical imaging and alloys |
| Dysprosium | Dy₂O₃ | 0.050% | Heat-resistant permanent magnets |
| Erbium | Er₂O₃ | 0.029% | Fibre optics and lasers |
| Terbium | Tb₄O₇ | 0.024% | High-performance magnets and phosphors |
Y₂O₃ is reported separately and excluded from Lion Rock’s TREO definition. Source: Table 3, Lion Rock Minerals ASX Announcement, 2 September 2026.
Scale of the dataset and what comes next
The results released in this announcement come from a retained-sample programme, not from the recently completed 761-hole campaign. A project-wide technical review identified retained drill material from Batches 4 and 5 of earlier Minta Est auger drilling. A total of 91 samples were assembled and submitted for ICP-OES analysis, with 90 valid full-suite assay results returned. Crucially, sample selection was governed by remaining sample mass and prior analytical status, not by the subsequently returned REE grade.
The scale of the broader dataset now entering the assay sequence is substantially larger. The targeted alluvial drill campaign, completed on 29 August 2026, delivered 761 holes for 3,485.43m across approximately 50km of rivers and tributaries, at an average drill depth of 4.58m. It generated 3,666 samples in total, including 2,163 panned samples. The first 638 samples, comprising Batches 31, 32, and 33, are now at the laboratory, with results to be reported in batches over coming weeks.
The three key upcoming catalysts management has outlined are:
- Further multi-element assay results from the recently completed 761-hole campaign, to be reported in batches over coming months
- Diamond drilling to test the depth extent and grade continuity of mineralisation below the 21.15% TREO saprolite zone, where auger drilling was unable to penetrate
- Mineralogical and petrological test work, including XRF, XRD, and QEMSCAN analysis, to establish mineral hosts, liberation characteristics, and potential recovery pathways
Theuns de Bruyn, CEO, Lion Rock Minerals (ASX: LRM)
“The discovery of high-grade rare earth mineralisation provides a transformational step change for the Project in terms of its scale and strategic nature.”
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Investment thesis: surface grades, open depth, and a dual-commodity platform
For investors assessing these results, several characteristics stand out beyond the headline intercepts.
Mineralisation starting at surface matters because it reduces the cost and complexity of early-stage extraction, removing the need to strip significant overburden before reaching economic material. The fact that multiple intervals end in mineralisation, with the highest-grade saprolite zone hitting auger refusal at 21.15% TREO, signals potential scale that has not yet been tested by deeper drilling.
Grade consistency across the dataset strengthens the exploration case further. Using zero-cut-off whole-hole averaging, which includes every valid assayed interval with no cherry-picking of sub-intervals, 8 of the 15 continuously assayed holes average more than 1.0% TREO over their full drilled depth, and 14 of 15 average at least 0.5% TREO. This is an indication of a broadly mineralised shallow system rather than isolated high-grade pockets.
The project also carries a dual-commodity dimension that distinguishes it from pure-play rare earth explorers. Minta is advancing as both a rare earth project and a rutile project, with a strategic relationship with Tronox.
It is important to note that these are in-situ exploration results only. No Mineral Resource Estimate has been established, and economic viability has not been demonstrated. The near-term catalyst pipeline, batch assay results from the 761-hole campaign, diamond drill mobilisation, and mineralogical test work, represents discrete news flow events that will progressively define the scale and nature of the system.
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