Geopolymers are inorganic polymers consisting of SiO4, AlO4- tetrahedra and charge balancing Group I cations dissolved in aqueous solution. The composition can exist over a solid solution range in the ternary phase diagram, but a composition that could lead to crystallization of a single compound is M2O•Al2O3•4SiO2•11H2O where M is the Group I cation. Geopolymers are made by mixing the aqueous waterglass solution (2MOH•2SiO2•10H2O) with metakaolin (Al2O3•2SiO2) powder under high shear and allowing to undergo dissolution, polycondensation and polymerization at room temperature. Various particulate, platelets, needles or chopped fiber reinforcements can be added to increase the viscosity of the liquid suspension which allow the mixture to be poured into a mold, applied as a coating, or 3D printed by appropriate tailoring of its viscosity, after which the composite sets under ambient conditions. The geopolymerizationmethod can be scaled up into sizes beyond those needing to be fired in a kiln. An organic base can also be used as an alternative charge balancing species which allows the casting of alkali-free aluminosilicate bodies and composites like geopolymers, setting at room temperature, and directfiring into alkali-free ceramics. The use of organic bases reduces the processing time and removes some limits on sample size compared to the ion exchange method used in the past