Platinum Sterling is a registered trademark name of American Bullion, Inc. The trademark covers a range of alloys whose primary constituents are platinum and silver, primarily used in jewellery. The range of Platinum Sterling alloys was developed in 2003 by Marc Robinson, and its solder was created by Chuck Bennett.
The platinum is used to replace at least some of the copper present in a typical sterling silver alloy, which provides a greater light reflectivity (by refining the grain structure) and resistance to tarnish (thought to be caused by oxidation of copper) than standard sterling silver.
Platinum Sterling is a cheaper alternative to white gold.[citation needed] It is also hard wearing and very white and so does not require rhodium plating like white gold.
Tests performed by the American Assay and Gemological Office showed that the whiteness of platinum-sterling alloys exceeds that of both sterling silver and white gold, and the new 3.5 percent platinum sterling displays six times more resistance to tarnishing than the standard sterling alloy.