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Fréjus

(Encyclopedia)Fréjus frāzhüsˈ [key], town, Var dept., SE France. With adjoining Fréjus-Plage, located ...

galena

(Encyclopedia)galena gəlēˈnə [key] or lead glance, lustrous, blue-gray mineral crystallizing usually in cubes, sometimes in octahedrons. It is the most important ore and the principal source of lead. It consist...

Guéret

(Encyclopedia)Guéret gārāˈ [key], town, capital of Creuse dept., central France. It is a market center ...

hallmark

(Encyclopedia)hallmark, mark impressed on silverwork or goldwork to signify official approval of the standard of purity of the metal, also called plate mark. The hallmark was introduced by statute in England in 130...

Cerro de Pasco

(Encyclopedia)Cerro de Pasco sĕrˈrō ᵺā päsˈkō [key], city, capital of Pasco dept., central...

neodymium

(Encyclopedia)neodymium nēˌōdĭmˈēəm [key], metallic chemical element; symbol Nd; at. no. 60; at. wt. 144.242; m.p. about 1,021℃; b.p. about 3,068℃; sp. gr. 7.004 at 20℃; valence +3. Neodymium is a lust...

thermoelectricity

(Encyclopedia)thermoelectricity, direct conversion of heat into electric energy, or vice versa. The term is generally restricted to the irreversible conversion of electricity into heat described by the English phys...

oxide

(Encyclopedia)oxide, chemical compound containing oxygen and one other chemical element. Oxides are widely and abundantly distributed in nature. Water is the oxide of hydrogen. Silicon dioxide is the major componen...

hardening

(Encyclopedia)hardening, in metallurgy, treatment of metals to increase their resistance to penetration. A metal is harder when it has small grains, which result when the metal is cooled rapidly. Sometimes small ar...

cerium

(Encyclopedia)cerium sērˈēəm [key] [from the asteroid Ceres], metallic chemical element; symbol Ce; at. no. 58; at. wt. 140.116; m.p. 799℃; b.p. 3,426℃; sp. gr. 6.77 at 25℃; valence +3 or +4. Cerium is a ...