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topaz
(Encyclopedia)topaz tōˈpăz [key], aluminum silicate mineral with either hydroxyl radicals or fluorine, Al2SiO4(F,OH)2, used as a gem. It is commonly colorless or some shade of pale yellow to wine-yellow; pale bl...quartz
(Encyclopedia)quartz, one of the commonest of all rock-forming minerals and one of the most important constituents of the earth's crust. Chemically, it is silicon dioxide, SiO2. It occurs in crystals of the hexagon...garnet
(Encyclopedia)garnet, name applied to a group of isomorphic minerals crystallizing in the cubic system. They are used chiefly as gems and as abrasives (as in garnet paper). The garnets are double silicates; one of ...Uris, Leon
(Encyclopedia)Uris, Leon yo͝orĭsˈ [key], 1924–2003, American novelist, b. Baltimore. Uris, who wrote many popular novels, is best known for the runaway best seller Exodus (1958), a fictional account of the ear...Korematsu, Fred Toyosaburo
(Encyclopedia)Korematsu, Fred Toyosaburo, 1919–2005, Japanese-American internment protester, b. Oakland, Calif. He was a shipyard welder when, after the Japanese raid on Pearl Harbor in 1942, President F. D. Roos...sapphire
(Encyclopedia)sapphire, precious stone. A transparent blue corundum, it is classified among the most valuable of gems. Sapphires are found chiefly in Madagascar, Sri Lanka, and Myanmar and also in Thailand, Tanzani...hardness
(Encyclopedia)hardness, property of matter commonly described as the resistance of a substance to being scratched by another substance. The degree of hardness is relative, different substances being compared with o...month
(Encyclopedia)month, in chronology, the conventional period of a lunation, i.e., passage of the moon through all its phases. It is usually computed at approximately 29 or 30 days. For the computation of the month a...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...sand
(Encyclopedia)sand, rock material occurring in the form of loose, rounded or angular grains, varying in size from .06 mm to 2 mm in diameter, the particles being smaller than those of gravel and larger than those o...Browse by Subject
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