 This study examined the use of reactive ultrafine fly ash, RUFA, as an alternative material for geopolymer production. It was found that RUFA geopolymers have similar properties to those produced from conventional fly ash, but with higher compressive strength due to the presence of calcium-based aluminosilicates and sodium-based aluminous complexes. Further studies could investigate the effect of varying concentrations of alkali activators on the strength of RUFA-based geopolymers. This article was authored by Weiting Lin, Keilong Lin, Kinga Kornijenko, and others.