Tarnish facts for kids

Tarnish is a thin layer that forms on the surface of some metals, making them look dull or dark. It's a bit like rust on iron, but it happens to other metals like silver, copper, and brass. This happens because of a chemical reaction between the metal and certain chemicals in the air, often oxygen or sulfur dioxide.

When a metal tarnishes, it means it's reacting with something around it. This reaction creates a new, thin layer on the metal's surface. This layer is usually a different color than the original metal, often darker or with a rainbow-like sheen.

What is Tarnish?

Tarnish is a type of corrosion. Corrosion is when a material, usually a metal, breaks down because of a chemical reaction with its environment. For example, when iron rusts, it's corroding. Tarnish is a milder form of corrosion that mostly affects the surface of the metal. It doesn't usually destroy the metal like rust can, but it does change its appearance.

How Does Tarnish Form?

Tarnish forms when metals like silver, copper, or brass come into contact with certain chemicals in the air. This is a type of chemical reaction called oxidation. In simple terms, the metal loses electrons to another substance, like oxygen or sulfur.

• Silver: Silver often tarnishes when it reacts with sulfur compounds in the air. These can come from things like rubber, some foods, or even pollution. The tarnish on silver is usually black or dark brown.
• Copper and Brass: Copper and brass (which is an alloy of copper and zinc) can tarnish when they react with oxygen in the air. This often creates a greenish or brownish layer called a patina.
• Aluminum: Aluminum also tarnishes very quickly when exposed to air, forming a thin, clear layer of aluminum oxide. This layer actually protects the aluminum underneath from further corrosion.

Why Do Metals Tarnish?

Metals tarnish because they are not completely stable on their own. They naturally want to react with other elements to form more stable compounds. The air around us contains many elements, including oxygen and sulfur, which are very reactive. When these reactive elements meet certain metals, a chemical reaction happens, and tarnish forms.

Cleaning Tarnish

Many people like to clean tarnish off their metal items to make them shiny again. The way you clean tarnish depends on the type of metal and how bad the tarnish is.

• Polishing: For many items, you can use a special metal polish. This polish contains tiny abrasive particles that gently rub off the tarnish layer.
• Chemical Cleaning: Some tarnish removers use chemicals to dissolve the tarnish. For example, silver tarnish can be removed using a chemical reaction with aluminum foil, baking soda, and hot water. This method reverses the tarnishing process.
• Prevention: The best way to deal with tarnish is to prevent it. You can store metals in airtight bags or containers, use anti-tarnish strips, or keep them away from things that cause tarnish, like humidity or certain chemicals.

Images for kids

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  Tungsten rods with evaporated crystals, partially oxidized with colorful tarnish

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  A Morgan dollar demonstrating a colourful form of toning on its reverse. While tarnishing on other metal objects is generally cleaned off, some toning on coins may be considered aesthetically pleasing or beneficial to the coin's value, and is therefore kept in situ.

See also

In Spanish: Deslustre para niños