Key Highlights

  • Reconnaissance sampling at Horn returned silver grades of up to 1,580 grams per tonne.
  • Dump material returned 0.47% antimony, an association the company says had not previously been recognised at the project.
  • All reported results are grab samples, which target visibly mineralised rock and do not represent average grades.
  • Diablo plans maiden drilling at Horn in early 2027.

Diablo Resources (ASX:DBO) released results from reconnaissance sampling at its Horn Silver Project in Utah on 9 November 2026. The company collected 65 rock samples across patented claims and reported silver grades of up to 1,580 grams per tonne.

Diablo is planning maiden drilling at Horn in early 2027.

A new antimony association

Dump material at the historical Horn Silver Mine returned 1,495g/t silver, 0.41g/t gold and 0.47% antimony. The company says antimony had not previously been recognised at the project.

The discovery of antimony matters because the metal has been designated a critical mineral in the United States, and prices rose sharply after China restricted exports. A silver project with antimony credits could attract interest from investors focused on critical minerals, although the economic significance depends on grades and volumes that have not yet been established.

The historical mine

The Horn Silver Mine produced 17 million ounces of silver at an average grade of 604g/t, according to the company. Diablo says the mineralised structure remains open along strike and at depth, a common situation at historical mines that closed before modern exploration techniques were available.

Results by prospect

At the Gossan prospect, samples returned 1,580g/t silver, 0.44g/t gold and 0.11% antimony, together with results of 826g/t and 464g/t silver. The interpreted structure extends about 400 metres and lies near an induced polarisation anomaly that the company is reprocessing to refine drill targets.

The Drum prospect returned up to 509g/t silver and 1.79g/t gold along a fissure that can be traced for more than 300 metres. At St Louis, three of 11 samples returned up to 30% zinc and 15.15% lead.

Grab samples, not grades

All of these results come from grab samples, which target visibly mineralised rock. Diablo notes that they do not represent average grades. Dump samples, in particular, reflect material that historical miners removed and may have been selected or concentrated, so they show what the mine contained rather than what remains in the ground.

Grab sampling is a useful first step for identifying mineralised structures and deciding where to drill, but it cannot indicate tonnage or continuity.

Management view

Chief Executive Lyle Thorne, who spent two weeks on site, said the results expanded the project's polymetallic footprint and had established a growing pipeline of high-priority drill targets across several mineralised structures.

Ownership and location

Diablo holds an 80% interest in Horn, which comprises 101 patented and 101 unpatented claims in the Frisco Mining District, about 20 kilometres west of Milford. Its Star Range Project lies about 15 kilometres away. Patented claims are privately owned land, which can simplify some permitting compared with federal ground, although drilling still requires approvals.

The broader context explains why historical silver districts in the western United States are being revisited. Silver prices have been firm, and US policy has encouraged domestic sources of critical minerals such as antimony. Many historical mines in Utah and Nevada closed before modern geophysics and drilling were available, so explorers see opportunities to find extensions or parallel structures. At the same time, historical records can be incomplete, and old workings can present safety and environmental challenges. Diablo's assessment of underground access will need to address those issues before any channel sampling can proceed. The company's Star Range Project nearby provides a useful second exploration front within the same district.

Next steps

Diablo plans to integrate the results into its regional target ranking, complete follow-up mapping and sampling on priority silver-antimony targets, and finalise permitting and drill planning.

It is also assessing whether the historical underground workings can be safely accessed for mapping and channel sampling. Underground access, if achievable, would provide more representative data than surface grab samples and could improve drill targeting before the early-2027 programme begins.