noble metal

/ˌnoʊbəl ˌmɛdl/

Other forms: noble metals

Definitions of noble metal

1. noun

   any metal that is resistant to corrosion or oxidation
   types:

   Au, atomic number 79, gold

   a soft yellow malleable ductile (trivalent and univalent) metallic element; occurs mainly as nuggets in rocks and alluvial deposits; does not react with most chemicals but is attacked by chlorine and aqua regia

   Pt, atomic number 78, platinum

   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

   Ag, atomic number 47, silver

   a soft white precious univalent metallic element having the highest electrical and thermal conductivity of any metal; occurs in argentite and in free form; used in coins and jewelry and tableware and photography

   24-karat gold, pure gold

   100 per cent gold

   gold dust

   the particles and flakes (and sometimes small nuggets) of gold obtained in placer mining

   coin silver

   a silver of the degree of purity established for making legal silver coins

   green gold

   a gold alloy (at least 14 karat gold with silver or silver and cadmium) that has a green appearance

   guinea gold

   22-karat gold from which guinea coins were made

   type of:

   metal, metallic element

   any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.