Solstice Minerals (ASX:SLS) hits 629m at 0.5% copper, dwarfing Nanadie’s resource

A 30.7m hit at 1.41% copper sits 300m below the resource boundary

Solstice Minerals (ASX:SLS) has released the first diamond drilling results from its Nanadie Copper-Gold Project in WA, and the numbers are the kind that get geologists at larger companies paying attention. The first diamond tail, NANRCD004, returned a combined intercept of 629.1 metres at 0.5% copper and 0.17g/t gold from surface to the end of hole, which is the sort of grade and length you typically see in much larger Andean porphyry systems.

The headline grabber is 30.7 metres at 1.41% copper and 0.34g/t gold from 461.5 metres, including 15 metres at 2.12% copper. There were also wide hits of 37.8 metres at 0.87% copper and 33 metres at 0.66% copper, all sitting more than 300 metres below the boundary of the existing 40.4 million tonne resource.

Importantly, this is one drillhole out of 13 diamond tails Solstice has completed. The remaining 12 are still being processed, with assays trickling out hole by hole over the coming months. The bull case here is straightforward. If the other holes look anything like this one, the current resource estimate is going to need a serious rework.

Why a 629m intercept changes how investors should value Nanadie

Most ASX-listed copper explorers report intercepts in the tens of metres. Solstice has just reported one that ran from surface to 629.1 metres without losing the thread. Combined grade across the entire length is 0.5% copper, which is well above the 0.4% average grade of the existing resource.

The combined RC and diamond intercept is comparable to what you see in globally significant copper systems. Nanadie has the added advantage of being on a granted Mining Lease in flat WA terrain, not at altitude in Chile or Peru. That changes the development equation materially.

The current resource sits at 162,000 tonnes of contained copper and 130,000 ounces of gold. We think this single drillhole is the strongest evidence yet that those numbers understate what is actually in the ground at Nanadie.

The visual sulphide match is the technical signal worth tracking

One of the more important details in the announcement is easy to miss. The assays from NANRCD004 closely match the zones where geologists previously logged visible chalcopyrite during core processing. Chalcopyrite is the primary copper sulphide mineral, and a tight match between what is logged visually and what the lab returns is a strong validation of the geological model.

That matters because the other 12 diamond holes have already been logged visually, and the team has flagged similar zones of mineralisation in several of them. The skeptical read on early drilling results is always that the first hole was a lucky hit. The visual-to-assay correlation gives us more confidence that the pending results will not disappoint.

Solstice has also confirmed Phase 2 RC drilling is progressing, with the deposit now interpreted as 100-200 metres wide, extending over 1.2km of strike, and open in every direction. The geological story has shifted from a defined small-to-mid resource into something potentially much bigger.

What investors should watch over the coming months

The next catalyst is NANRCD005, a follow-up diamond tail that extends host geology roughly 500 metres below the resource boundary. If that hole returns anything like NANRCD004, the resource upgrade conversation moves from possible to inevitable.

Beyond that, results from the other 11 pending diamond tails will arrive on a hole-by-hole basis through the second half of 2026. The Phase 2 RC program continues at 13,000 metres of step-out drilling and pre-collar work for further diamond holes.

The Investors Takeaway for Solstice Minerals

Solstice has done the hard part. It has proven the Nanadie system extends well beyond the existing resource boundary, that it carries high-grade zones at depth, and that the visual logging matches the lab results. The investment case from here rests on conversion. Twelve more diamond holes need to produce results that are at least in the same neighbourhood as NANRCD004.

Our concern is that single-hole exuberance is a well-known trap in exploration investing. The Nanadie thesis only holds if the broader system genuinely is what management thinks it is. The next six months of assay releases will provide the answer. Investors looking for more in-depth coverage of ASX-listed copper-gold explorers can find it at stocksdownunder.