Production of cement, the binder component of concrete, accounts for an estimated 9% of global CO2 emissions. To improve sustainability of cement and concrete use, two strategies have emerged: (1) to consume less cement by partially replacing it with supplementary cementing materials (SCMs), or (2) to consume less concrete by improving its durability (e.g., as hindered by reactive aggregates). Many such SCMs and reactive aggregates are well-represented as amorphous aluminosilicates. The current research investigates simplified metrics that reflect the composition and structure of these aluminosilicates while enabling prediction of their aqueous reactivity in alkaline environments, and the associated impact on cement paste and mortar properties. New means to control aluminosilicate reactivity are developed, alongside improved understandings that will aid in the future use of data-driven learning tools to study and solve similar material problems.