Ore zoning depends on the relative solubility of metallic compounds in the ore solution. If the metals are carried as a single type of ion or compound, possible methods of transport may be selected on the basis of a regular progression of one or more properties with zoning position. A table of recent values of physical and chemical properties for Sn, Cu, Zn, Pb, Sb, and Hg, in order as metals representative of mineral zones, shows that no property varies linearly with zoning position either for the element or the common mineral. The relative stability of covalent-bonded complex ions, calculated by a new thermodynamic method for any one type of anion, matches the zoning sequence. The examination of sulfide complexes strongly supports the latter as the more probable type in respect to both geologic and experimental evidence.