OD6 Metals Re-Assays Reveal 13% Grade Boost at Horseshoe Fluorspar

Revised Assays Unlock Higher Fluorspar Grades

OD6 Metals (ASX:OD6) has delivered a significant upgrade to its Horseshoe fluorspar deposit grades at the Quinn Fluorspar Project in Nevada. The company announced that re-assays of channel samples, using a more precise ALS Global technique, revealed an average 12.9% uplift in calcium fluoride (CaF2) grades compared to initial results reported in July 2026. This recalibration confirms Horseshoe as a notably high-grade fluorspar resource, with standout intervals such as 50 metres at 79.3% CaF2 and 15 metres at 85.8% CaF2 from surface exposures.

Assay Technique Shift Corrects Underestimation

The original assay method (F-ELE82), employed by ALS Global in North America, was found to underestimate fluorine content in the ultra-high-grade fluorspar matrix at Horseshoe. ALS advised that matrix effects caused a negative bias in the initial results. OD6 responded by sending residual pulps to ALS Perth for re-assaying with the F-XRF24 technique, which involves sample fusion and high-powered X-ray fluorescence analysis. This method, previously used in metallurgical testing, consistently returned higher grades, aligning with the recent metallurgical samples that showed fluorspar grades of 90% and above. Going forward, OD6 will adopt the F-XRF24 assay for all samples to ensure accuracy.

Broad, Near-Surface Mineralisation with Expansion Potential

The channel sampling program covered an 80-metre-wide exposed zone within a tabular mineralised body estimated to be 15 to 30 metres thick, with mineralisation remaining open both up-dip and down-dip. The high consistency of grades across 120 channel samples, averaging 74.8% CaF2, underscores the deposit's continuity and scale. Notably, 85% of samples graded above 50% CaF2, with 31 samples exceeding 90% CaF2 and a peak of 98.8%. This breadth and tenor of mineralisation diverge from typical narrow-vein fluorspar deposits, enhancing Horseshoe's appeal as a premium fluorspar source in a globally tight market.

Strategic Importance in US Critical Minerals Supply

Fluorspar is classified as a critical mineral in the United States, which currently imports 100% of its fluorspar consumption, predominantly from China. OD6's Quinn Project, situated in Nevada, ranked second globally for mining attractiveness, positions the company to potentially supply a strategically vital mineral domestically. The company highlights the high grades and scale of Horseshoe as key to producing premium Metspar and Acidspar products, with US Acidspar prices reaching approximately US$654 per tonne in July 2026. This pricing context amplifies the commercial significance of OD6's advancing metallurgical and ore-sorting programs.

Next Steps Focus on Drilling and Product Development

With the assay revision complete, OD6 is now concentrating on demonstrating the deposit's scale through planned drilling, for which permitting is underway. Concurrent metallurgical testwork and ore-sorting studies aim to optimise recovery and product quality, tailoring output for the US market's Metspar and Acidspar demand. The company’s Managing Director Brett Hazelden emphasised the importance of the combination of grade, width, and scale, suggesting Horseshoe could evolve into a significant high-grade fluorspar deposit. These developments complement OD6’s broader portfolio, including rare earth and copper projects, as the company leverages its critical minerals expertise across multiple jurisdictions.