Why this tin and antimony explorer is in focus

Dart Mining NL (ASX:DTM) is a Victoria-based explorer whose recent announcements centre on a planned maiden diamond drilling campaign at the historic Walwa tin mine in north-east Victoria. The company says drilling is scheduled to begin in October 2026, and that is the main reason the stock is worth a closer look. It is also selling other Victorian projects.

What the company does and its stage

Dart is an early-stage exploration company with no reported production revenue. Its Walwa, Cudgewa and Berringama tenements in Victoria are described as 100% owned. It also has a joint venture interest in the Coonambula gold-antimony project in Queensland.

Walwa: what has and has not been established

In an announcement dated 25 August 2026, Dart compiled historical data for Walwa, including 150 historical drill holes totalling 7,672 metres and recorded historical tin production of 162 tonnes. Historical estimates in that release are not JORC-compliant, and Dart states it is not treating them as current Mineral Resources or Ore Reserves, noting the old data lack quality-control records.

On 16 September 2026 the company reported assays from four rock-chip samples collected in June. The best, an in-situ grab from the pit wall, returned 3.96% tin with 165 parts per million tantalum. Dart cautioned the samples are selective. These are exploration results, not a resource.

Dart's priority drilling targets are a possible tin-rich greisen zone presumed to lie 400 to 600 metres below surface and stacked pegmatite dykes at depth. The company's 7 October 2026 release is titled as maiden drilling to test the Walwa system at depth, with nine proposed drill sites subject to access approvals.

Funding, asset sales and dilution

The latest cash figure we could verify is from the July 2026 notice of meeting, which showed cash of A$402,638 at 31 December 2025. We did not locate the June 2026 quarterly report, so current cash and burn are not confirmed here.

That notice set out a binding deal to sell the Mount Unicorn, Sandy Creek, Tallandoon and Corryong projects to Indigo Metals Limited for A$3.6 million in cash plus 17.5 million Indigo shares valued at A$0.20 each, with Dart retaining a 2.5% net smelter Royalty on antimony. It also described a Placement of about A$1.3 million before costs at A$0.025 a share, comprising 31,456,293 and 20,970,862 shares. Shareholders approved all resolutions at the 10 August 2026 extraordinary general meeting. Completion of the Indigo sale is conditional on Indigo's IPO and ASX listing. The approved Options add potential dilution.

Dart has also lodged a notice of general meeting dated 12 October 2026. We could not read its contents, so we do not describe its purpose.

Sector context and risks

Tin and tantalum are used in electronics, and antimony Supply is concentrated. Exploration is inherently uncertain, and small explorers often raise Capital repeatedly. Specific risks for Dart include reliance on historical data, the unconfirmed Indigo completion timetable, and the cost of a deep drilling programme.

Upcoming milestones

The confirmed near-term item is the start of Walwa diamond drilling, which Dart guides to October 2026. Assay results would follow.