The Boss-Bixby deposit is located on the line dividing Iron and Dent Counties and belongs to the Southeast Missouri Precambrian Iron Metallogenic Province. The sequence of events leading to the formation of the deposit is reviewed. The mineralization occurred after intrusion of intermediate magma, but prior to the intrusion of granite. The ore minerals present are the following in the order of deposition: magnetite, ilmenite, giekielite, hematite, rutile, pyrite, molybdenite, cobaltite, chalcopyrite, bornite, sphalerite, galena, limonite, chalcocite, and cuprite. Four different methods of zoning are presented. Partial pressures of oxygen and sulphur [sic], as well as temperature controlled sequential deposition of ore. This deposit is class...