The Collaborative International Dictionary
Silicification
Silicification \Si*lic`i*fi*ca"tion\, n. [See Silicify.] (Chem.) Thae act or process of combining or impregnating with silicon or silica; the state of being so combined or impregnated; as, the silicification of wood.
Wiktionary
silicification
n. (context geology English) impregnation with silica; petrification