the treatment of alluvial tin is not

  • 31Vietnam — /vee et nahm , nam , vyet , vee it /, n. 1. Official name, Socialist Republic of Vietnam. a country in SE Asia, comprising the former states of Annam, Tonkin, and Cochin China: formerly part of French Indochina; divided into North Vietnam and… …

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  • 32Natural History (Pliny) — Naturalis Historia, 1669 edition, title page. The title at the top reads: Volume I of the Natural History of Gaius Plinius Secundus. The Natural History (Latin: Naturalis Historia) is an encyclopedia published circa AD 77–79 by Pliny the… …

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  • 33Mining in Angola — Angola is the third largest producer of diamonds in Africa and has only explored 40% of the diamond rich territory within the country, but has had difficulty in attracting foreign investment because of corruption, human rights violations, and… …

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  • 34Spain — /spayn/, n. a kingdom in SW Europe. Including the Balearic and Canary islands, 39,244,195; 194,988 sq. mi. (505,019 sq. km). Cap.: Madrid. Spanish, España. * * * Spain Introduction Spain Background: Spain s powerful world empire of the 16th and… …

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  • 35Texas — • Includes geography, history, demographic, and government information Catholic Encyclopedia. Kevin Knight. 2006. Texas     Texas     † …

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  • 36Mining industry of Angola — Mining in Angola is an activity with great economic potential since the country has one of the largest and most diversified mining resources of Africa. Angola is the third largest producer of diamonds in Africa and has only explored 40% of the… …

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  • 37Timeline of Aboriginal history of Western Australia — This is a Timeline of Aboriginal history of Western Australia 1629 1829Aboriginal life in the two centuries from 1629 to 1829, was characterized by the increased presence of Europeans around the Western Australian coastline. First contact,… …

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  • 38Mexico — /mek si koh /, n. 1. a republic in S North America. 97,563,374; 761,530 sq. mi. (1,972,363 sq. km). Cap.: Mexico City. 2. a state in central Mexico. 6,245,000; 8268 sq. mi. (21,415 sq. km). Cap.: Toluca. 3. Gulf of, Mexican, Golfo de México /gawl …

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  • 39Iridium — (pronEng|ɪˈrɪdiəm) is a chemical element that has the symbol Ir and atomic number 77. A very hard, brittle, silvery white transition metal of the platinum family, iridium is the second densest element and is the most corrosion resistant metal,… …

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  • 40Devonian Period — Interval of geologic time from 417 to 354 million years ago; it was the fourth period of the Paleozoic Era. During the Devonian, a giant continent was situated in the Southern Hemisphere (see Gondwana), and other landmasses were located in the… …

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