Perlite is a volcanic mineral abundant in Turkey, China, Japan, the US and several EU countries. Expanded perlite has been widely used in producing lightweight concrete. Recent research suggests the use of ground perlite as a pozzolan to partially replace cement. This study investigates strength properties of high-volume perlite mixtures and the influence of chemical and thermal activation on their strengths at early and later ages. Both activation types can increase early-strength gain rates and strength values achieved by pure portland cement mixtures can be exceeded in as early as 28 days with some activators and be maintained. Findings indicate that ground perlite is a successful natural pozzolan. Results also suggest that perlite-only mixtures can be activated to produce geopolymers. The consistency of its chemical composition compared to those of artificial pozzolans and its abundance in several developing countries makes perlite attractive for producing sustainable concretes with reduced carbon footprints.