Argentium silver (patented in 1998) is a brand of modern tarnish-resistant silver alloys, containing either 93.5%, 94% or 96% silver. Argentium alloys replace some of the

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

in the traditional

sterling silver Sterling silver is an alloy composed mass fraction (chemistry), by weight of 92.5% silver and 7.5% other metals, usually copper. The sterling silver silver standards, standard has a minimum millesimal fineness of 925. ''Fineness, Fine silver'' ...

(92.5%

silver Silver is a chemical element; it has Symbol (chemistry), symbol Ag () and atomic number 47. A soft, whitish-gray, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. ...

+ 7.5% copper) with the

metalloid A metalloid is a chemical element which has a preponderance of material property, properties in between, or that are a mixture of, those of metals and Nonmetal (chemistry), nonmetals. The word metalloid comes from the Latin language, Latin ''meta ...

germanium Germanium is a chemical element; it has Symbol (chemistry), symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid or a nonmetal in the carbon group that is chemically ...

. Argentium 935, Argentium 940 and Argentium 960 alloys exceed the standard required for

hallmark A hallmark is an official Mark (sign), mark or series of marks struck on items made of metal, mostly to certify the content of noble metals—such as platinum, gold, silver and in some nations, palladium. In a more general sense, the term ''Wikti ...

ing as

, and Argentium 960 silver meets the standard for hallmarking as

Britannia silver Britannia silver is an alloy of silver containing 11 ozt 10 dwt (i.e. 11½ troy oz.) silver in the pound troy, equivalent to , or 95.833% by weight (mass) silver, the rest usually being copper. This standard was introduced in England by Act o ...

(95.84% silver).

Origins and description

Argentium silver is the result of research at the Art and Design Research Institute (ADRI), School of Art & Design,

Middlesex University Middlesex University London (legally Middlesex University and abbreviated to MDX) is a public research university based in Hendon, northwest London, England. The university also has campuses in Dubai and Mauritius. The name of the university is ...

, by Peter Johns and colleagues. The project began in 1990 with research on the effects of

additions to silver

alloy An alloy is a mixture of chemical elements of which in most cases at least one is a metal, metallic element, although it is also sometimes used for mixtures of elements; herein only metallic alloys are described. Metallic alloys often have prop ...

s. Germanium was discovered to impart the following properties to sterling silver: *

firescale Firestain is a layer of oxides that is visible on the surface of objects made of metal alloys containing copper when the object is heated, as by a jeweler heating a ring to apply solder during a repair. On copper-containing alloys of gold or of si ...

elimination * high

tarnish Tarnish is a thin layer of corrosion that forms over copper, brass, aluminum, magnesium, neodymium and other similar metals as their outermost layer undergoes a chemical reaction. Tarnish does not always result from the sole effects of oxygen in ...

resistance *

precipitation hardening Precipitation hardening, also called age hardening or particle hardening, is a heat treatment technique used to increase the yield strength of malleable materials, including most structural alloys of aluminium, magnesium, nickel, titanium, and so ...

and simple heat-hardening properties * increased

ductility Ductility refers to the ability of a material to sustain significant plastic Deformation (engineering), deformation before fracture. Plastic deformation is the permanent distortion of a material under applied stress, as opposed to elastic def ...

* increased

thermal A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example ...

and

electrical resistance The electrical resistance of an object is a measure of its opposition to the flow of electric current. Its reciprocal quantity is , measuring the ease with which an electric current passes. Electrical resistance shares some conceptual paral ...

* environmental advantages Many of these properties significantly affect the traditional methods of working silver. For instance the absence of firescale eliminates tedious and time-consuming steps required by the silver worker using traditional sterling silver. It also eliminates the need for plating the final product which is often done on manufactured items because of the problems introduced by firescale. Tarnish resistance is of significant importance to both silver workers and the wearer of silver jewellery. Argentium silver was patented and is trademarked by Argentium Silver Company, UK.

Origins and description

Physical properties

Footnotes

References

Further reading

External links