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gem, ornamental mineral or organic substance
(Encyclopedia)gem, commonly, a mineral or organic substance, cut and polished and used as an ornament. Gems also are used as seals (items of assurance) and as talismans (good-luck charms). For birthstones, see mont...gold
(Encyclopedia)gold, metallic chemical element; symbol Au [Lat. aurum=shining dawn]; at. no. 79; at. wt. 196.96657; m.p. 1,064.43℃; b.p. 2,808℃; sp. gr. 19.32 at 20℃; valence +1 or +3. Gold is very ductile and...mirror
(Encyclopedia)mirror, in optics, a reflecting surface that forms an image of an object when light rays coming from that object fall upon it (see reflection). Usually mirrors are made of plate glass, one side of whi...glass
(Encyclopedia)glass, hard substance, usually brittle and transparent, composed chiefly of silicates and an alkali fused at high temperature. Glass has become invaluable in modern architecture, illumination, elect...hydrogen
(Encyclopedia)hydrogen hīˈdrəjən [key] [Gr.,=water forming], gaseous chemical element; symbol H; at. no. 1; interval in which at. wt. ranges 1.00784–1.00811; m.p. −259.14℃; b.p. −252.87℃; density 0.08...lighting
(Encyclopedia)CE5 Incandescent lamp CE5 Basic fluorescent lamp lighting, light produced by artificial means to allow visibility in enclosures and at night. For stage lighting, see scene design and stage ligh...asteroid
(Encyclopedia)CE5 The asteroid belt lies between the orbits of Mars and Jupiter. Gaps where no asteroids are found are called Kirkwood gaps. The Trojan asteroids share Jupiter's orbit with the planet. asteroid,...Burkina Faso
(Encyclopedia)CE5 Burkina Faso burkēˈnə fäˈsō [key], republic (2020 est. pop. 20,900,000), 105,869 sq mi (274,200 sq ...Madagascar
(Encyclopedia)CE5 Madagascar mădˌəgăsˈcär [key], officially Republic of Madagascar, republic (2015 est. pop. 24,234,000), 226,658 sq mi (587,045 sq km), in the Indian Ocean, separated from E Africa by the ...Brazil
(Encyclopedia)CE5 Brazil brəzĭlˈ [key], Port. Brasil, officially Federative Republic of Brazil, repub...Browse by Subject
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