Three main minerals make up most of the ore production in the Silver Valley. Galena (PbS or lead(II) sulfide) is the most important ore mineral found in the Coeur d’Alene District veins. Galena is present in veins throughout the district. Sphalerite ((Zn,Fe)S) is the second most important ore mineral, present in at least small amounts in most veins. The sphalerite is an important source of zinc throughout the ore belts. The third most abundant ore mineral is tetrahedrite (Cu,Fe)12Sb4S13. However, the tetrahedrite is responsible for the majority of the silver produced by the Silver Valley, as it’s the tetrahedrite interspersed in the galena of the district that makes it so argentiferous.