323 samples, biotite plus K-feldspar together account for more than 60% of the mode, underscoring the dominance of K bearing mineral phases. Figure 3 – Modal mineralogy of samples collected from the N3, N4, N5, and S11 mines in wt%, with the equivalent limit of 25 vol% for quartz. Chlorite is the main silicate mineral present, accounting for a large portion of the Al, Fe, and Mg content. Actinolite and epidote host most of the Ca partitioning, followed by plagioclase, scapolite, and calcite. Calcite is essentially the only carbonate identified and is abundant in many samples, contributing more than half of the Ca content in several cases. Samples RMS11, RMS12, and RMS13 differ mineralogically from the drillcore samples, showing markedly higher carbonate proportions associated with hydrothermal veining and recrystallization described macroscopically. The actinolite identified in sample SN4FD00096AE022 (Figure 4) exhibits typical amphibole cleavage and Mg–Fe atomic proportions consistent with the tremolite–actinolite series, characterized by Mg:Fe ratio > 1 and Mg/(Mg+Fe) ≤ 0.9, the minimum threshold required to classify it as tremolite according to IMA classification criteria.
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