“Geopolymer” is a term coined by Joseph Davidovits in referance to a family of alumino-silicate cements. “Polymer” because the material consists of repeating molecular units covalently bonded into a macro-molecule. “Geo” indicates that this material is mineral in orgin, rather than organic, and that the chemical pathways involved occur naturally in the forming of some types of rocks.
In this chemical system, soluable sodium aluminates and silicates precipitate into a solid material. Often, the source of the alumina and silica are clays (specifically kaolin) or rocks which are attacked by a sodium or potassium hydroxide solution. The precursor mineral is made more susceptible to chemical attack by strong heating in a kiln, which dissorders the molecular structure.
Thus, geopolymers are also essentially ceramic, and the techniques and machinery for working with geopolymers are the same as is used in the ceramic industry. This realization, that “ceramics” are achievable without intense kilns, has influenced the fields of archeology (especially of ancient egypt) and engineering.