Precious Metals: Silver Jewelry
Sterling Silver Jewellery
Source: Australia, Canada, Mexico, Peru, United States
Silver is a lustrous, soft transition metal that is number 47 on the periodic table of chemical elements. Silver has the highest electrical conductivity of any element, and the highest thermal conductivity of any metal. In its natural form, silver is combined with sulfur, arsenic, antimony, or chlorine and occurs in various ores such as argentite (Ag2S), horn silver (AgCl) and pyrargyrite (Ag3SbS3). The principal sources of silver are copper, copper-nickel, gold, lead and lead-zinc ores. Silver is also produced during the electrolytic refining of copper.
The name "silver" comes from the Anglo-Saxon word seolfor, and the Althochdeutsch (Old High German) word silabar. The atomic symbol (Ag) is derived from the Latin word argentum which is derived from the Indo-European root arg, meaning "shiny."
Sterling silver tension bracelet |
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Silver Nugget (photo: US Gov) |
Silver has been used by man since the 4th millennium BC, and the metal is mentioned in the book of Genesis. Silver is one of the only jewelry metals that is permitted to be worn by men of the Islamic fait, as the Prophet Muhammad wore a silver signet ring.
The silver used in jewellery is typically "sterling silver" (aka "standard silver") which is an alloy of silver and copper. For a metal to be labeled as "sterling silver" the silver alloy must contain at least 92.5 percent pure silver. Sterling is found in the grades: 800 sterling, 925 sterling, 958 sterling, and 999 sterling, which is identified using the precious metals hallmarking system.
Silver Ore (photo: US Gov) |
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Mesh silver necklace & brushed silver earrings |
Commercial grade fine silver is at least 99.9% pure silver and purities greater than 99.999% are available. Mexico is the world's largest silver producer. Silver is currently valued at approximatly 1/45th the price of gold.
Argentium Sterling (AS)
Argentium Sterling (AS) is comprised of 92.5 percent pure silver, 1 to 2 percent germanium, and about 6 percent copper. The argentium sterling alloy is less susceptible to tarnishing than is sterling silver because the germanium element forms a germanium oxide "skin" on the metal's surface, acting as a barrier to oxidization. Argentium Sterling Silver is also resistance to firescale (firestain).
Physical Properties of Silver
| Name, Atomic Symbol, # |
silver, Ag, 47 |
| Element Category |
transition metals (Group 11, Period 5, Block d) |
| Crystal Structure |
cubic, face centered |
| Specific gravity (SG) |
19.32 |
| Mohs Hardness Scale |
2.5 |
| Vickers Hardness (VHN or HV) |
251 MPa |
| Melting Point |
1763.2F (961.78C, 1234.93K) |
| Boiling Point |
3924F (2162C, 2435K) |
| Magnetic Ordering |
diamagnetic |
| Chemical Composition |
(Ag), (Ag2S), (AgCl) |
Oxidized Sterling Silver Jewelry
One of the popular techniques for adding an aged or weathered patina to silver is to oxidize a textured silver surface (antiquing, antiqued finish), blackening it, and giving it the look of antiquity. the oxidation process is done using a chemical called "liver of sulphur," which is commonly available at jewelry supply companies. The sulphur is dissolved in hot water, and the silver is soaked until the desired patina is achieved.
Silver earrings with oxidized patina |
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Brushed silver & gold earrings |
Another technique that is used to achieve a satin patina is to use a rotary tumbler (motorized rock tumbler) and polished steel shot, tumbling the piece for several hours, or until the desired luster is achieved. Using a wire brush (brass scratch-brush) or fine steel wool will also provide a soft, satin finish (burnished) to silver and gold.
Any tarnish that builds up on the surface can be removed with a polishing cloth that is specifically designed for silver. To preserve the natural finish of your silver jewellery you can use a jewelry silver bag, and keep the pieces in a cool, dry location.
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