Shares of Tertiary Minerals plc surged as much as 10.3% to £0.08 on August 24 after the London-listed explorer released new drill results from its Mushima North copper-silver project in Zambia — a move that, for a company valued in the low single-digit millions, amounts to a make-or-break moment in its bid to prove a commercially viable deposit. Tertiary Minerals Pops 10% on Zambia Copper Hits, but Can a £3.5 Million Company Afford to Prove What It Found?
Shares of Tertiary Minerals (TYM.L) jumped 10.3% to £0.08 on August 24 after the AIM-listed explorer released final preliminary drill results from Zambia that significantly firmed up its copper-silver discovery. For a company with a market capitalisation of £3.61m and approximately 5.15 billion shares in issue , even modest drill news can violently move the stock — and today's results were better than modest.
• Broad, Near-Surface Copper Zones Add Bulk to a Potential Deposit. Final Phase 4 results showed broad copper intersections including 66 metres grading 0.30% copper from just 14 metres depth and 68 metres at 0.28% copper from 13 metres, with higher-grade pockets of 7 metres at 0.52% and 5 metres at 0.57%. The fact that mineralisation starts almost at the surface matters because shallow deposits are far cheaper to mine. The results support Tertiary's existing exploration target of 15–30 million tonnes grading 40–60 grams per tonne silver equivalent. If confirmed by lab assays, that tonnage range could underpin a meaningful small mine — but the word if looms large.
• Silver Readings Could Be the Real Prize — or a Mirage. Preliminary portable XRF readings returned silver values up to 115 g/t in the higher-grade zone and 144 g/t in the wider target, though Tertiary cautioned that pXRF analysis is less reliable for silver.
All samples have been submitted for certified laboratory analysis , and those results will either validate or deflate the silver story. If real, silver credits would dramatically improve the project's economics.
• The Clock Is Ticking Toward a Maiden Resource — and More Cash Burn. Tertiary is targeting a formal JORC Mineral Resource Estimate before the end of 2026. A JORC resource is the industry-standard measure that tells investors how much metal is actually in the ground. Achieving one would be the company's most significant milestone yet. Following lab results, Tertiary plans metallurgical testing and resource modelling — both expensive steps. The company's wider outlook remains constrained by persistent losses and continued cash consumption. With no revenue and no dividend, more fundraising is likely, which would dilute existing shareholders.
• Upside Remains, but It's Untested Territory. Mineralisation remains open to the northwest, southwest, and at depth , and separate copper mineralisation was identified at the Western Zone, roughly 900 metres away . That geographic spread hints at a bigger system. But for a four-person company worth less than a London flat, every positive drill hole must be weighed against the funding reality required to convert discovery into dollars.