Mineralogy is an earth science focused around the chemistry, crystal structure, and physical properties of minerals. This book presents new research on mineralogy, including a review on the chemical mineralogy of ornamental rock waste and water treatment plant waste, which are produced world-wide in large scales and are a concerning issue for industry and environmentalists alike. This book also presents new research on smelting, a process that liberates the metallic element of an ore from its compound and separates it from the waste part of the charge. The environmental impact of smelting activities is discussed, as well as the combination of smelting with gasification for treatment of solid waste and the production of alternative fuel.