This collection honoring Professor Jiann—Yang Hwang focuses on characterization and processing development in minerals, metals, and materials. Topics include but are not limited to: • Characterization methodology of minerals, metals, and materials • Microwave—assisted material processes • Recycling and reuse of metallurgical byproducts • Materials for hydrogen storage • Wastewater treatment and environmental protection • Natural materials for value—added applications • Principles and interactions of material characterization and manufacturing processing