How to Test Silver

Perhaps you've recently acquired a silver item from a dubious online store, or it may have been a gift from a friend who found it. Alternatively, you might just want to confirm whether an antique family heirloom is truly silver. Regardless of the reason, knowing how to test silver is important. Silver is a versatile chemical element. Sterling silver is composed of 92.5% silver and 7.5% other metals, primarily copper. This type of silver is more durable than pure silver. Pure silver, being relatively soft, is often referred to as "fine silver." Many items that are silver-plated (only coated with a thin layer of silver) can sometimes be mistaken for solid silver. Scroll down to step 1 to begin testing your silver item.

Check for the mark. Items marketed as silver in international markets are generally stamped with a hallmark that indicates their silver content. Be cautious if the item does not have this stamp. It could still be real silver, but it may have been crafted in a country where stamping isn't mandatory.

Look for the international silver grade stamp. Use a magnifying glass to examine the silver item. Silver sold on the international market is usually stamped with numbers such as 925, 900, or 800. These numbers indicate the percentage of silver in the item. The number 925 means the item contains 92.5% silver, while 900 and 800 refer to silver contents of 90% and 80%, respectively, often referred to as 'coin silver.'

Test with a magnet. Use a strong magnet, like a neodymium magnet. Silver is paramagnetic, meaning it has a very weak magnetic effect. If the magnet sticks firmly to the item, it likely contains ferromagnetic material and is not silver.

• Note that some other metals also don't attract magnets and could be used to counterfeit silver. It is best to combine the magnet test with another method to ensure the core is not made of a different metal.

Slide the magnet on the silver bar. If you're testing a silver bar, you can try another magnetic test. Tilt the bar at a 45-degree angle and let the magnet slide down. The magnet will slowly move down the surface of the bar. It may sound unusual, but silver is paramagnetic, and the neodymium magnet generates an eddy current in the silver, acting as a braking force and slowing down the magnet's descent.

Get a few ice cubes. Place some ice cubes in the freezer and leave them until you're ready to test your silver. While silver and ice may not seem related, this test is based on the fact that silver is the best heat conductor among common metals and alloys, with copper being the second best.

• This method works well for testing coins and silver bars, but is more challenging when testing silver jewelry.

Place the ice cubes on the silver item. Watch closely as the ice cube. It will begin to melt immediately as if it had been placed on something hot, rather than something at room temperature.

Use the sound test with coins. Silver produces a pleasant bell-like sound when struck, especially when tapped against another metal object. If you'd like to hear the sound of real silver before testing, try finding a U.S. quarter minted before 1965. These coins are made of 90% silver, whereas quarters made after 1964 are composed of a copper-nickel alloy. The older coins will emit a high-pitched, clear, resonant sound, while newer coins will produce a duller, flatter sound.

Drop your coin onto a flat surface from about 15 cm high. If the coin rings like a bell, you're most likely holding a genuine silver coin. If the sound is dull, it's likely that the silver has been mixed with other metals.

Perform a chemical analysis test. Use a chemical analysis if no silver hallmark is visible on the item. Be sure to wear gloves, as you will be using a corrosive acid to test the purity of the material. Acid is harmful to skin.

• Note that this method could slightly damage the silver item. If you suspect it might be a valuable piece, it’s best to determine the silver content using one of the other methods described in this article.

Buy a silver acid test kit. You can purchase these kits online from platforms like Amazon or eBay, or from jewelry stores. The acid test is very effective for pure silver, but if you suspect the item is silver-plated, you’ll need to use a jewelry file to scrape a small section to expose the layer beneath the plating.

Find a hidden spot on the item and scrape a small mark. This will reveal the metal underneath for the acid test. Use a metal file to scrape a small section below the outer plating of the silver item.

• If you prefer not to scrape or leave any acid marks on the silver, you can use a black stone. Black stones are typically included in silver test kits or sold in the same jewelry stores. Rub the silver item on the surface of the stone to create a relatively wide streak, about 4 cm in length.

Drop a small amount of acid onto the scraped area. If the acid touches any un-scraped parts, it will also affect the outer polish of the silver item. If using a black stone, drop the acid onto the streak on the stone’s surface.

Observe the surface where acid was dropped. You will need to analyze the color that appears after the acid is applied to the silver surface. Follow the instructions and the color scale provided in the test kit. Typically, the color scale of the test kit looks like this:

• Bright Red: pure silver
• Dark Red: 925 silver
• Brown: 800 silver
• Green: 500 silver
• Yellow: lead or tin
• Dark Brown: brass
• Blue: nickel

Drop a small amount of bleach onto the item. Silver will tarnish very quickly when exposed to strong oxidizing agents like regular bleach.

Observe if the item tarnishes or shows no reaction. If it quickly tarnishes and turns black, it is silver.

• If you're using chemical tests to determine the quality of silver, remember to wear gloves, as nitric acid is an extremely corrosive substance.
• Try to buy silver from reputable sources, such as stores selling quality jewelry.

• If nitric acid comes into contact with your skin, wash it off immediately with water as it is a corrosive substance. After washing thoroughly, sprinkle baking soda on the affected area.