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Using electron microprobe (EMP) and laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to collect major and rare-earth elements (REE), respectively, from apatites from the 1991 Mt. Pinatubo juvenile eruption products, we have determined that two statistically distinct populations of apatite exist. One population crystallized from the juvenile basaltic melt (basalt apatites) and the other population crystallized from the main dacitic magma body (silicic apatites). Both populations contain high-S apatites (>0.7wt.% SO₃). Apatite has previously been shown to be a potential monitor for magmatic sulfur contents via numerous proposed coupled substitutions of P⁵⁺ for S⁶⁺. However, simple apatite/melt partitioning cannot account for high-S silicic apatites, which grew from a silicic melt with an apparent maximum S concentration of ~80ppm. Disparate apatite morphology (i.e. skeletal and acicular for …