Shares of Tertiary Minerals (AIM: TYM) climbed 4.6% to $0.06 after the AIM-listed explorer confirmed its largest-ever Zambian drilling campaign is now underway — a 4,000-metre reverse circulation programme targeting the A1 silver oxide discovery at its Mushima North project. The move bucked a softer broader market, suggesting investors are betting specifically on what comes out of the ground.
The Biggest Drill Programme in Company History Has a Clear Goal
The 4,000-metre campaign is the largest Tertiary has undertaken in Zambia, aimed at converting an early-stage exploration target of 15–30 million tonnes at 40–60 g/t silver equivalent into a formal, independently verified mineral resource.
At the upper end, that implies up to 58 million ounces of silver equivalent. With silver trading near $58 per ounce today , the theoretical in-ground value at the top end would exceed $3 billion — wildly disproportionate to Tertiary's market capitalisation of just £3.45 million . That gap is why the stock moves on every drilling headline.
Prior Results Were Encouraging, but the Deposit Is Unproven
Previous drilling returned a standout 97-metre intersection grading 56 g/t silver, 0.43% copper and 0.19% zinc — strong by junior-explorer standards. The deposit appears to be a near-surface, tabular body roughly 500m long, 300m wide and up to 75m thick, though mineralisation remains open in multiple directions and at depth. Until infill drilling proves continuity, these are promising data points, not bankable resources.
Cash Is Thin and Dilution Risk Is Real
For the six months to March 2026, Tertiary posted a pre-tax loss of £328,231 and ended the period with just £77,730 in cash, having since raised £1 million via a share placing.
The fundraise provides enough capital to complete the planned programme , but any follow-up work — or delays from weather — would likely require another equity raise from a company with approximately 5.15 billion shares already outstanding .
Deeper Sulphide Potential Could Change the Story — or Remain Untested
MD Richard Belcher flagged the potential for deeper sulphide mineralisation beneath the surface oxide layer, calling it "potentially a game changer." That upside is real but speculative; the transition from oxide to sulphide mineralisation has yet to be tested. Results from this campaign, expected over 6–12 weeks, will determine whether Tertiary stays a story stock or starts becoming a resource company.