platinum

1. n. A metallic element, intermediate in value between silver and gold, occurring native or alloyed with other metals, also as the platinum arsenide (sperrylite). It is heavy tin-white metal which is ductile and malleable, but very infusible, and characterized by its resistance to strong chemical reagents. It is used for crucibles, for stills for sulphuric acid, rarely for coin, and in the form of foil and wire for many purposes. Specific gravity 21.5. Atomic weight 194.3. Symbol Pt. Formerly called platina. Source: opted
2. n. a heavy precious metallic element; grey-white and resistant to corroding; occurs in some nickel and copper ores and is also found native in some deposits Source: wordnet
3. A metallic element, intermediate in value between silver and gold, occurring native or alloyed with other metals, also as the platinum arsenide (sperrylite). It is heavy tin-white metal which is ductile and malleable, but very infusible, and characterized by its resistance to strong chemical reagents. It is used for crucibles, for stills for sulphuric acid, rarely for coin, and in the form of foil and wire for many purposes. Specific gravity 21.5. Atomic weight 194.3. Symbol Pt. Formerly called platina. Platinum black (Chem.), a soft, dull black powder, consisting of finely divided metallic platinum obtained by reduction and precipitation from its solutions. It absorbs oxygen to a high degree, and is employed as an oxidizer. -- Platinum lamp (Elec.), a kind of incandescent lamp of which the luminous medium is platinum. See under Incandescent. -- Platinum metals (Chem.), the group of metallic elements which in their chemical and physical properties resemble platinum. These consist of the light platinum group, viz., rhodium, ruthenium, and palladium, whose specific gravities are about 12; and the heavy platinum group, viz., osmium, iridium, and platinum, whose specific gravities are over 21. -- Platinum sponge (Chem.), metallic platinum in a gray, porous, spongy form, obtained by reducing the double chloride of platinum and ammonium. It absorbs oxygen, hydrogen, and certain other gases, to a high degree, and is employed as an agent in oxidizing. Source: webster
4. A metallic element, intermediate in value between silver andgold, occurring native or alloyed with other metals, also as theplatinum arsenide (sperrylite). It is heavy tin-white metal which isductile and malleable, but very infusible, and characterized by itsresistance to strong chemical reagents. It is used for crucibles, forstills for sulphuric acid, rarely for coin, and in the form of foiland wire for many purposes. Specific gravity 21.5. Atomic weight194.3. Symbol Pt. Formerly called platina. Platinum black (Chem.), asoft, dull black powder, consisting of finely divided metallicplatinum obtained by reduction and precipitation from its solutions.It absorbs oxygen to a high degree, and is employed as an oxidizer.-- Platinum lamp (Elec.), a kind of incandescent lamp of which theluminous medium is platinum. See under Incandescent.-- Platinum metals (Chem.), the group of metallic elements which intheir chemical and physical properties resemble platinum. Theseconsist of the light platinum group, viz., rhodium, ruthenium, andpalladium, whose specific gravities are about 12; and the heavyplatinum group, viz., osmium, iridium, and platinum, whose specificgravities are over 21.-- Platinum sponge (Chem.), metallic platinum in a gray, porous,spongy form, obtained by reducing the double chloride of platinum andammonium. It absorbs oxygen, hydrogen, and certain other gases, to ahigh degree, and is employed as an agent in oxidizing. Source: adambom
5. n:100 n. a heavy precious metallic element; grey-white and resistant to corroding; occurs in some nickel and copper ores and is also found native in some deposits Source: ecdict

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