Rockfire Resources has identified additional zinc and germanium mineralisation at its Molaoi project in Greece, expanding the geological picture of a deposit that could become a European source of critical raw materials for semiconductors, advanced communications equipment and defence technologies.
The latest drilling has revealed multiple mineralised horizons across the approximately two-kilometre-long deposit, prompting a substantial revision of the geological model. As a result, publication of Molaoi’s first JORC-compliant germanium mineral resource estimate has been delayed by several weeks.
The London-listed company is also evaluating ore-sorting technology and preparing further technical studies ahead of a feasibility study planned for 2027. The proposed development could combine zinc, lead, silver and germanium production, although the commercial potential of the additional mineralisation still needs to be established through laboratory analysis and metallurgical testing.
New drilling identifies additional zinc-bearing structures
The latest campaign included drill hole HMO-022, which reached a depth of 308.90 metres and intersected five separate zinc-bearing lodes.
One mineralised interval at approximately 293 metres depth extended around 1.5 metres, with individual portable X-ray fluorescence readings reaching 47.7% zinc. These measurements are preliminary and should not be interpreted as laboratory-confirmed grades. Core samples have been submitted for independent analysis to establish the actual metal concentrations and geological characteristics.
The new intersections have complicated the existing resource interpretation, requiring consultants to revise the geometry of mineralised structures, including their interpreted dip, and reassess previously modelled intersections.
More than 1,360 individual zinc and germanium lode intercepts are now being evaluated across the deposit, according to Rockfire. GeoRes Mining Consultants is undertaking the updated assessment, which is intended to establish the first formal germanium resource alongside a revised zinc resource model. The delay reflects the additional geological work required to incorporate the newly identified mineralised zones. Their potential contribution cannot be quantified until grade, thickness, continuity and recoverable metal content have been independently assessed.
Existing polymetallic resource supports development potential
Molaoi already contains a JORC Inferred mineral resource of approximately 15 million tonnes grading 7.26% zinc, 1.75% lead and 39.5 grams per tonne silver.
The company’s published figures indicate contained quantities of approximately:
- 1.09 million tonnes of zinc
- 260,000 tonnes of lead
- 19.1 million ounces of silver
Germanium represents an additional potential source of value, but it has not yet been quantified through a dedicated mineral resource estimate.
Earlier laboratory-confirmed results from drill hole HMO-021 provided evidence of germanium occurring alongside the principal zinc mineralisation. The hole intersected 11 metres grading 5.0% zinc, 19 grams per tonne silver and 8 grams per tonne germanium, including narrower intervals with higher metal concentrations. These results support further investigation of the deposit’s germanium potential, although its distribution and recoverability remain important unanswered questions.
Rockfire is continuing diamond drilling, with hole HMO-023 underway. The programme aims to improve geological confidence and potentially upgrade parts of the existing Inferred resource to Indicated classification. Such an upgrade would support more detailed mine planning and future economic assessments. It would also be important for financing, as lenders and investors require greater certainty over recoverable material, mining methods, production schedules and capital requirements.
TOMRA tests ore-sorting technology for Molaoi
Alongside resource development, Rockfire is investigating whether automated ore sorting could improve the economics of a future mining operation.
The company commissioned Norwegian technology specialist TOMRA to conduct initial tests using material representative of anticipated Molaoi ore. Testing has been completed, but results had not been disclosed in the latest announcement.
The objective is to separate mineralised material from lower-value rock before conventional grinding and processing. If the technology proves effective, pre-concentration could increase the grade of feed entering the processing plant while reducing the volume of material requiring energy-intensive grinding. Potential benefits include lower electricity consumption, improved processing efficiency and reduced pressure on certain waste-management systems.
The commercial case will depend on separation performance, equipment costs and the amount of valuable material retained in the processing stream.
A particularly important consideration is whether ore sorting can preserve germanium-bearing minerals alongside zinc and other recoverable metals. A system that improves zinc grades but rejects significant quantities of germanium could reduce the overall value of the deposit. Consequently, the technology must be assessed according to its impact on total metal recovery and project economics, rather than zinc concentration alone. The test results are expected to contribute to technical work supporting the planned 2027 feasibility study.
Germanium strengthens Molaoi’s strategic importance to Europe
The potential addition of germanium broadens Molaoi’s significance beyond conventional zinc, lead and silver production.
Germanium is used in semiconductors, infrared optical systems, high-speed communications, advanced electronics and certain solar technologies. Its importance to these industries has made it a strategic raw material for the European Union. Global supply is highly concentrated, with China remaining the dominant producer. This creates exposure for European industrial consumers seeking alternative sources of critical minerals.
The EU’s Critical Raw Materials Act aims to strengthen domestic extraction and processing while diversifying supply relationships. A commercially viable European source of germanium could therefore attract interest from industrial buyers, strategic investors and specialist financing institutions. For Rockfire, however, identifying germanium mineralisation is only the beginning of the development process. The metal is commonly recovered as a by-product of base-metal processing, so the company must demonstrate that it can be efficiently extracted from Molaoi ore.
This requires metallurgical testing to establish recovery rates, processing requirements, product specifications and the availability of suitable downstream refining partners. Without demonstrated recovery and a viable route to market, even a substantial germanium resource would not automatically translate into commercial production.
Further technical studies will determine project viability
Rockfire has also completed a drone-based magnetic survey across the Molaoi licence area. The data are being processed and interpreted to improve understanding of geological structures that could influence the location and continuity of mineralisation.
Combined with ongoing drilling, the survey is expected to help refine the geological model and guide future exploration. The next development phase will bring together several key workstreams: laboratory-confirmed drilling results, an updated zinc resource, a maiden germanium resource, improved geological confidence and the results of ore-sorting and metallurgical tests. These findings will need to support a broader assessment of mining methods, infrastructure, permitting, environmental requirements, capital expenditure and operating costs.
Germanium could improve Molaoi’s economic prospects if it can be recovered alongside zinc and lead without creating disproportionate processing costs. Its potential financial contribution remains unquantified.
The project already has an established polymetallic resource, but its evolution into a strategically important European critical-minerals operation depends on proving that the additional germanium mineralisation is both technically recoverable and commercially valuable.
The revised geological model may ultimately expand the development opportunity. The decisive milestones will be the maiden germanium resource estimate, independent assay results and metallurgical studies, which will establish whether Molaoi can support a viable supply of zinc and strategically important germanium for European industry.
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