Greatly appreciate your analyses and insight, particularly your...

Greatly appreciate your analyses and insight, particularly your earlier metallurgy posts - they helped me a lot when originally attempting to evaluate those risks. I have also pored over the preliminary metallurgy report, and relevant case studies in the literature - Araxa REE and Mt Weld niobium - for breadcrumbs. Some thoughts below - I have no geo background, so excuse my ignorance where it is evident.

Firstly, per the WA1 preliminary metallurgical report, the samples are “taken from previously reported oxide-enriched mineralised intervals of drillholes LURC23-026 and LURC23-033”, which I believe means sampled from the highly weathered zone (26 contained 13m @ 5% and 33 contained 10m @ 4%).

The report says apatite is the primary phosphate-bearing mineral at Luni in these samples. In both Araxa REE and Mt Weld niobium, there appears to be virtually no remnant of apatite in the weathered zone (detailed in the above papers), with alteration to phosphate-bearing minerals, primarily gorceixite and crandallites respectively. The fine-grained matrix (potpourri, to use your expression) of these minerals is blamed for the observed poor liberation properties in the linked papers, along with leaching of the desired elements to other host minerals, and fine-graining of the primary bearing minerals. So, optimistically, I speculate that analogous alteration processes have not occurred in the weathered zone at Luni, nor, relatedly, something comparable to the REE leaching at Araxa / Nb leaching at Mt Weld, nor the fine-graining.

See also the images of fine Sr-niobate / ferroniobate grains embedded in crandallite (Mt Weld), as compared to the large liberated pyrochlore grain imaged in Slide 14 of the WA1 Noosa presentation - “ LURC23033 (COMPOSITE SAMPLE FROM 40-48M)” - again, sampled from the high-grade 4% Nb2O5 interval in hole 33. Of course, we can assume significant selection bias in these image choices.

Lastly, I take the “over 85% of the dominant niobium bearing mineral as being ‘well-liberated’ or ‘high-grade middlings in the -150+38 µm fraction.” as indicative that fine-graining in the niobium bearing minerals has not occurred, at least in these samples, i.e. it would seem likely that the pyrochlore grain distribution is of a similar or greater characteristic length scale to the particle size interval, as it would require a contrived distribution of grains to achieve those liberation statistics from significantly finer grains given that pyrochlore only makes up ~5-10% of the ore. Is this a reasonable inference? Again, the monazite grade class distribution and on-surface distribution in the Araxa REE paper contrast sharply, i.e. the majority of the monazite-bearing particles exhibit very poor liberation characteristics.

"Certainly the strong horizontal supergene layer at the base of heavily lateritic clays suggests chemical remobilisation, not physical concentration through weathering deflation." - I'm missing the geological intuition here, so would you mind elaborating on this, i.e. how would you expect the supergene layer to be distributed if resulting from physical concentration through weathering deflation? Thanks!