A rare and expensive group of metals that resist corrosion such as gold (Au), iridium (Ir), platinum (Pt), palladium (Pd), ruthenium (Ru), and rhodium (Rh), some of which may be found in catalytic converters.
precious metals that cannot be altered by air or water (silver, gold, platinum)
Metals which are non-reactive, inert or resistant to oxidation. Traditionally includes, gold, silver and copper.
Metals which do not have great chemical activity, particularly gold, which is neither corroded by moisture nor affected by oxygen or ordinary acids.
The noble metals are gold, platinum, and silver. These are metals that are relatively impervious to chemical action.
Metals such as gold, silver and platinum which are resistant to corrosion by all but the most powerful acids.
Metallic elements with surfaces that do not readily oxidize in air; e.g., gold, silver, platinum.