A source of sand is proposed as an educational tool to aid in the identification of silica mineralogies and textures susceptible to alkali–silica reaction. This particular silica sand originates in the southern portion of the state of Veracruz, Mexico, and exhibits a wide variety of lithologies, A thin section produced from a cross-section through a mortar bar subjected to ATSM C1260 Standard Test Method for Potential Alkali Reactivity of Aggregates (Mortar–Bar Method) exhibits plentiful examples of reactive silica.