Sterling silver is an alloy of silver and copper. The silver alloy is 92.5% pure silver and 7.5% copper—creating a much more durable and much less malleable metal. These qualities make it far more suitable for use in jewelry and other items, but it also comes with downsides.
Fine silver, which is 99.9% pure silver, has a beautiful, near-perfect polish and barely tarnishes. But sterling silver will tarnish over time due to its combination with copper. The good news is that when it’s polished, sterling silver retains nearly the same perfect color as fine silver.
Any silver alloy with over 92.5% silver is considered sterling silver.
How do you know if it’s sterling silver?
The quality of silver jewelry is denoted by its millesimal fineness. This is a number that represents the percentage of silver in the alloy. A silver piece will have the fineness stamped into it—this is called a hallmark.
There are a few different hallmarks that you might see on sterling silver jewelry. These usually refer to the percentage of silver in the alloy—92.5%. Here’s a list of some of the common stamps you’ll see on sterling silver.
Sometimes the silver won’t be hallmarked. Not every country makes it a legal requirement, and in this case, it can be much harder to tell if it really is sterling silver or not.
There are a few basic tests you can do to find out, though. The problem is that the tests will tell you whether it’s silver, not necessarily sterling silver.
The first is to see whether the jewelry is magnetic. Sterling silver jewelry will not be magnetic, so if a strong magnet attracts the piece, it likely has a magnetic base metal. This test will not tell you if it’s sterling silver, but it will tell you if there’s a cheap non-precious metal underneath!
Another quick test is to dab a small amount of bleach onto the silver jewelry. Silver will immediately turn a blackish color. If it does change color, you know that the jewelry is made out of silver of some sort—but not necessarily sterling silver. It could be silver plate or a lower quality silver.
To make sure you’re not buying the wrong kind of silver, here are a few other varieties you may come across.
Fine silver - 99.9% pure silver and usually marked with a 999. Very rarely found in jewelry.
Britannia silver - 95% pure silver alloy. Usually marked with a 950. Slightly softer than sterling silver.
Coin silver - 90% pure silver. Less pure than sterling silver, coin silver was historically used in silver coin manufacturing.
Nickel silver - Nickel silver has no silver content at all. Instead, it’s an alloy of a few metals, including copper, nickel, and zinc. Nickel silver is made to be an affordable metal that resembles sterling silver.
What about silver plate? It gets a little more confusing when it comes to silver-plated jewelry. This is jewelry made of a non-precious base metal coated with a very thin layer of silver. The silver plate could be sterling silver, but because the item isn’t solid silver, it’s worth much less and can be damaged far more easily.
So what is sterling silver? It’s the standard for high-quality silver jewelry. Just remember—look for the 925 sterling silver hallmark. If the silver piece isn’t hallmarked, it can be hard to tell if you have real sterling silver. Try the magnet and bleach tests to make sure you don’t have a fake!
Genuine sterling silver is beautifully bright, and the neutral color means that a sterling silver piece will suit any style or occasion.
Sterling silver will also keep its value over time, and all you have to do is make sure it stays polished!