Hydration of the system tuff-lime-gypsum with and without small addition of Portland cement has been studied in the range 25-85 degrees C and up to 28 days curing. The simultaneous formation of calcium silicate and trisulphoaluminate hydrates makes cured products suitable for manufacturing pre-formed building elements, provided that curing temperature is at least 40 degrees C. Portland cement acts as a true catalyst as its addition enhances the formation of both the hydration products. Among other sources of reactive silica and alumina, such as granulated blast furnace slag and coal fly ash, tuff has proved to be the most reactive material. The process studied in this paper offers an opportunity for optimally employing tuff by recycling quarry dust.