Introduction.- Definitions and Nomenclature.- Tectonic Settings of Potassic Igneous Rocks.- Selected Type-Localities of Potassic Igneous Rocks from the Five Tectonic Settings.- Primary Enrichment of Precious Metals in Potassic Igneous Rocks.- Direct Associations Between Potassic Igneous Rocks and Gold-Copper Deposits.- Direct Associations Between Potassic Igneous Rocks and Copper-Gold Deposits on Craton Margins.- Indirect Associations Between Lamprophyres and Gold-Copper Deposits.- Halogen Contents of Mineralized Versus Unmineralized Potassic Igneous Rocks.- Implications for Mineral Exploration in Arc Environments.- Characteristics of Some Gold-Copper Deposits Associated with Potassic Igneous Rocks.