Redox-active minerals often have complex electrochemical properties that are difficult to quantify and explain. Quantification is difficult because many redox-active minerals are poorly conductive, prone to dissolution, and capable of undergoing reversible and irreversible structural changes during redox cycling. Explaining a mineral's electrochemical properties is frequently challenging because minerals can undergo complex ion transport processes in their structures and undergo charge redistribution processes that occur within the crystal lattice on long time scales. In this talk, I will present the insights I have gained from studying environmentally relevant iron- and manganese-bearing minerals over the past 15 years. The presentation will include how electrochemical analyses can be used to quantify the thermodynamic properties of minerals and how these properties relate to their redox reactivities with environmentally relevant phases. The talk will also cover persisting challenges that exist in this field.