topaz
topaz A nesosilicate mineral, Al2SiO4(OH,F)2; sp. gr. 3.5–3.6; hardness 8; orthorhombic; colourless, pale yellow, pale blue, yellowish, or sometimes pink; often transparent; vitreous lustre; crystals are prismatic and often bipyramidal with the vertical faces striated, but it can also be massive and granular; cleavage perfect basal orthorhombic; typically occurs in granite pegmatites, rhyolite, and quartz veins, and extensively as an accessory mineral in granites, associated with fluorite, tourmaline, beryl, and cassiterite, also in alluvial deposits. It is associated with pneumatolytic action (see PNEUMATOLYSIS) and is a constituent of greisen. The original cairngorms (see QUARTZ) were topaz crystals. It is named after Topazos Island in the Red Sea.
topaz
to·paz / ˈtōpaz/ • n. 1. a precious stone, typically colorless, yellow, or pale blue, consisting of a fluorine-containing aluminum silicate. ∎ a dark yellow color. 2. a large tropical American hummingbird (genus Topaza) with a yellowish throat and a long tail.
Topaz
Topaz ★★★ 1969 (PG)
American CIA agent and French intelligence agent combine forces to find information about Russian espionage in Cuba. Cerebral and intriguing, but not classic Hitchcock. Based on the novel by Leon Uris. 126m/C VHS, DVD . John Forsythe, Frederick Stafford, Philippe Noiret, Karin Dor, Michel Piccoli; D: Alfred Hitchcock; W: Samuel A. Taylor; C: Jack Hildyard; M: Maurice Jarre. Natl. Bd. of Review ‘69: Director (Hitchcock), Support. Actor (Noiret).
topaz
topaz Transparent, glassy mineral, aluminium fluosilicate, Al2SiO4(F,OH)2, found in pegmatites. Its crystals are orthorhombic system columnar prisms. Topaz is colourless, white, blue or yellow; some large crystals are of gem quality. Hardness 8; r.d. 3.5.
More From encyclopedia.com
Fluorite , fluorite (fluorspar, Blue John) Mineral, CaF2;sp. gr. 3.2; hardness 4; cubic; often yellow, green, blue, or purple, but can be colourless, pink, red,… Cinnabar , cinnabar The commonest mercury mineral, HgS; sp. gr. 8.0–8.2; hardness 2.0–2.5; trigonal; scarlet-red to brownish-red; vermilion streak; adamantine l… Archipelago , ar·chi·pel·a·go / ˌärkəˈpeləˌgō/ • n. (pl. -gos or -goes) a group of islands. ∎ a sea or stretch of water containing many islands. ORIGIN: early 16th… Celestite , celestite Mineral SrSO4 which may form a solid solution series with barite; sp. gr. 3.9–4.0; hardness 3.0–3.5; orthorhombic; faint blue to colourless… Meranti , red meranti See SHOREA.
meranti See SHOREA. Red-shanked Douc Langur , douc langur (Pygathrix nemaeus) See CERCOPITHECIDAE.
Pygathrix nemaeus (douc langur) See CERCOPITHECIDAE.
You Might Also Like
NEARBY TERMS
topaz