Predominance diagram, Pb-S-O 6 100oK s PbsO4 PbSo4.2Pbo PbS PbSO4→PbO PbSO4.4Pbo Pb Pbo 12 20-18-16-14-12-108_6 Log io(oxygen partial pressure, atmosheres)Predominance diagram, Pb-S-O