Abstract: The present invention provides a method and mixture for use in forming strong light-weight aggregate and includes by weight about; 68% to 95% fly-ash, 2% to 10% hydrated lime, and 3% to 12% alkali hydroxide such as Sodium Hydroxide. While many types of fly-ash may be used, Type F or Type C fly-ash are preferred. The admix is mixed with water to form a slurry including water in a range of 10% to 25% by weight of the dry mixture and the slurry is then compacted. The compacted slurry is then cured such as by using a rotary kiln or by in situ open air curing. The cured slurry is then allowed to hydrolyzed to form a hard material which then may be crushed and optionally screened to form an aggregate having a particular size or range of sizes.