"Geopolymers are revolutionary for the concrete industry. Any type of rock aggregate can be used, and concrete made with geopolymeric binder is practically indistinguishable from natural stone. ...This is unprecedented technology; no tremendous heat or pressure is required... Geopolymeric concrete sets rapidly at room temperatures to form synthetic stone, beautiful in appearance and abundant with unprecedented properties."
January 1, 1970
https://en.wikiquote.org/wiki/Joseph_Davidovits