Толковый словарь английского языка Oxford English Reference - silica

n. silicon dioxide, occurring as quartz etc. and as a principal constituent of sandstone and other rocks. Phrases and idioms silica gel hydrated silica in a hard granular form used as a desiccant. Derivatives siliceous adj. (also silicious). silicic adj. silicify v.tr. & intr. (-ies, -ied). silicification n. Etymology: L silex -icis flint, after alumina etc.