silica — hard silicon dioxide, 1801, Modern Latin, from L. silex (gen. silicis) flint, pebble, on model of alumina, soda … Etymology dictionary
silica — ► NOUN ▪ silicon dioxide, a hard, unreactive, colourless compound which occurs as quartz and in sandstone and many other rocks. DERIVATIVES siliceous adjective. ORIGIN from Latin silex flint , on the pattern of words such as alumina … English terms dictionary
silica mineral — Any of the forms of silicon dioxide (SiO2), including quartz, tridymite, cristobalite, coesite, stishovite, melanophlogite, lechatelierite, and chalcedony. Various kinds of silica minerals have been produced synthetically. * * * Introduction… … Universalium
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).… … Useful english dictionary
silica — [ sɪlɪkə] noun silicon dioxide, a hard, unreactive, colourless compound which occurs as quartz and as the principal constituent of sandstone and other rocks. [SiO2.] Derivatives siliceous sɪ lɪʃəs (also silicious) adjective Origin C19: from L.… … English new terms dictionary
alumina-silica refractories — Смотри алюмосиликатные огнеупоры … Энциклопедический словарь по металлургии
Activated alumina — is manufactured from aluminium hydroxide by dehydroxylating it in a way that produces a highly porous material; this material can have a surface area significantly over 200 square metres/g. The compound is used as a desiccant (to keep things dry… … Wikipedia
refractory — refractorily, adv. refractoriness, n. /ri frak teuh ree/, adj., n., pl. refractories. adj. 1. hard or impossible to manage; stubbornly disobedient: a refractory child. 2. resisting ordinary methods of treatment. 3. difficult to fuse, reduce, or… … Universalium
catalysis — catalytic /kat l it ik/, adj., n. catalytical, adj. catalytically, adv. /keuh tal euh sis/, n., pl. catalyses / seez /. 1. Chem. the causing or accelerating of a chemical change by the addition of a catalyst. 2. an action between two or more… … Universalium
Precious Stones in the Bible — Precious Stones in the Bible † Catholic Encyclopedia ► Precious Stones in the Bible Precious stones are stones remarkable for their colour, brilliancy, or rarity. Such stones have at all times been held in high esteem everywhere,… … Catholic encyclopedia
