Let’s be realistic for a moment.
While the valuation upside for ESR’s limestone asset is clearly compelling if they hit the 500Mt JORC milestone, I think it’s equally important to address the elephant in the room:
Is it actually achievable in the time remaining?
As of now, Estrella has announced a drilling program totalling just 12,992 meters, with an average planned hole depth of around 80 to 100 meters. That’s roughly 130 to 160 drill holes, assuming no major overruns or duplicates.
For a bulk industrial commodity like limestone, JORC-compliant resource definitions — even at the Inferred level — typically require:
• Broad-scale surface mapping and sampling
• Regularly spaced drilling grids (often 200m × 200m for Inferred)
• Verified lithology and density data
• Geological continuity modeling over large lateral areas
Assuming a 200m × 200m grid spacing, and targeting a 10–15 km² area (which would be consistent with a 500Mt potential, assuming ~2.5–2.7 t/m³ density), we’d be looking at several hundred holes to establish sufficient coverage and confidence — or at minimum, tight drilling along stratigraphic corridors with clear lateral projection.
So unless ESR has legacy data, extensive outcrop mapping, or intends to use geophysical proxies, the scale of this drill-out looks extremely ambitious.
And that brings us to the key point:
We know REM is now clearly engaged. But they are not the buyer — they are the middleman, and it’s apparent they already have buyers sourced.
They’ve drawn the line:
• JORC 500Mt by 30 September 2025
• Scoping Study by 30 November 2025
• Port/export approvals by 31 December 2025
These are not aspirational targets — they’re contractual obligations. REM can’t proceed with minimum offtake unless ESR delivers.
So now, it’s over to ESR to remain compliant with those terms.
Investors need clarity on:
Is the program on track?
How will 500Mt be defined from a sub-13,000m drill campaign?
Is more drilling planned or budgeted?
What geological model or assumptions support resource extension beyond physical drilling?
I’m optimistic on the project’s scale — I believe they have more limestone than they’re letting on, potentially well above 1Bt in situ — but we need transparency on how this will be executed in real time.
September 30th isn’t just a deadline. It’s a line in the sand that converts blue-sky into bankable reality — or not!
