Platinum sterling
Encyclopedia
Platinum Sterling is a registered trademark name of American Bullion, Inc. The trademark is applied as the name of a range of alloy
s whose primary constituents are platinum
and silver
, and which are primarily used in jewellery. The range of Platinum Sterling alloys were developed in 2003 by Marc Robinson, and Chuck Bennett created the solder of the alloy.
alloy 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 which does not incorporate platinum.
Platinum Sterling is a cheaper alternative to white gold. It is also hard wearing and very white so it 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, with the new 3.5 percent platinum sterling displaying six times more resistant to tarnishing than standard sterling alloy.
and 1%, 3.5% or 5% platinum. A small amount of gallium
can also be added to the composition to provide ease of manufacture of the alloy.
The patent application for Platinum Sterling claims:
And from the same claim:
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...
s whose primary constituents are platinum
Platinum
Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...
and silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
, and which are primarily used in jewellery. The range of Platinum Sterling alloys were developed in 2003 by Marc Robinson, and Chuck Bennett created the solder of the alloy.
Properties
The platinum is used to replace at least some of the copper present in a typical sterling silverSterling silver
Sterling silver is an alloy of silver containing 92.5% by mass of silver and 7.5% by mass of other metals, usually copper. The sterling silver standard has a minimum millesimal fineness of 925....
alloy 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 which does not incorporate platinum.
Platinum Sterling is a cheaper alternative to white gold. It is also hard wearing and very white so it 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, with the new 3.5 percent platinum sterling displaying six times more resistant to tarnishing than standard sterling alloy.
Composition
The composition of Platinum Silver is published; three alloys are commercially available, all containing standard .925 sterling silverSterling silver
Sterling silver is an alloy of silver containing 92.5% by mass of silver and 7.5% by mass of other metals, usually copper. The sterling silver standard has a minimum millesimal fineness of 925....
and 1%, 3.5% or 5% platinum. A small amount of gallium
Gallium
Gallium is a chemical element that has the symbol Ga and atomic number 31. Elemental gallium does not occur in nature, but as the gallium salt in trace amounts in bauxite and zinc ores. A soft silvery metallic poor metal, elemental gallium is a brittle solid at low temperatures. As it liquefies...
can also be added to the composition to provide ease of manufacture of the alloy.
The patent application for Platinum Sterling claims:
And from the same claim: