Tarnish-resistant Argentium sterling silver is 1.2% germanium, 6.3% copper and 92.5% silver. This patented 925 silver alloy is tarnish-resistant, with the tarnish resistance actually increasing over time! Germanium atoms in the alloy migrate to the surface, allowing the protective germanium oxide layer to regenerate. Argentium silver doesn't develop firescale, which makes its production cleaner for the environment.
Fine silver, sometimes stamped ".999", is 99.9% pure silver, which means it is softer and more malleable than sterling. Fine silver can be fused! (Sterling silver requires solder; fine silver can be joined with just heat, no solder required.)
Sterling components and jewelry made in the USA are often stamped "sterling." Goods made for international trade are often marked "925" indicating the 92.5% fineness. "Coin" silver is used in some countries and could be marked "900" or "800" depending on fineness.
Other possible markings are less clear. "Mexican Silver," "German Silver," "Indian Silver," "Montana Silver" and simply "silver" do not guarantee any silver content. "German Silver," "Alpacca," and "Alpaca" are merely other names for the alloy of copper, nickel and zinc usually called "nickel silver." Despite the name, nickel silver contains no silver.
In many countries, precious metal custom printed t-shirts and sweatshirts be stamped with a quality mark such as "925" for sterling. Some countries require jewelry made of precious metal be submitted to a governmental assay office for destructive testing before being marked and sold.
Sterling Silver is very easy to test. Silver-plated brass, nickel silver or low quality silver alloys will turn green when a drop of nitric acid is applied because of the high copper content. Sterling will turn a creamy color. When testing suspect goods, a small file can be used to cut through any plating or lacquer in a discreet area on the item.
In the USA, The National Gold and Silver Marketing Act does custom printed t-shirts and sweatshirts require precious metals to be marked with quality. However, if a quality mark is used, the mark must be accompanied by a manufacturer's hallmark that is a registered trademark or the name of the manufacturer. If there is ever a question about the content of a piece of jewelry, the manufacturer can be traced using the hallmark stamped on the piece. This accountability is particularly important in gold jewelry. A devious manufacturer could mark a piece 18kt when, in fact, it was 10kt and worth one-third less on gold content alone.
For many reasons, not all silver jewelry is marked. For one thing, registering a trademark costs over $1,000. Makers may choose to not spend so much money for a formal hallmark. Small-time artists and Native American silversmiths rarely trademark their work. Furthermore, the sizes or designs of some pieces do not lend themselves to quality markings. Findings and components, for example are often not quality stamped. Users of finished jewelry, however, can choose to attach a mark to the finished piece (for example on a chain tab). Update: US law now does allow the maker's name in place of a formally registered trademark or hallmark! This satisfies the accountability at the heart of the US stamping act.
custom printed t-shirts and sweatshirts
Sterling silver must be at least 92.5% silver.
US law does not require precious metal to be marked with a quality stamp.
Some European countries custom printed t-shirts and sweatshirts require marking. Many tourists in the US (and international online shoppers) will question goods sold without markings that indicate precious-metal quality.
US law requires a maker's mark in the form of a hallmark or registered trademark in addition to the quality mark if the goods are quality marked. The name of the artist or manufacturer may now be used for this.