The Properties of Real Gold and Its Resistance to Rust

No, real gold does not rust or tarnish. Exposure to air and water can cause some metals to tarnish or rust, but pure gold doesn’t because it is chemically inert. However, alloyed gold can sometimes tarnish, but it won’t rust.

Tarnish vs. Rust – Understanding the Difference

Tarnish and rust result from exposing metals to water and oxygen, elements that cause metals to oxidize. For instance, oxidized iron is known as iron oxide, and oxidized copper is copper oxide. 

Metal oxides usually form on the outer layer of the metal, and they behave differently. Iron oxide or rust is more destructive than other metal oxides because it flakes, causing iron to eat away gradually. Rust has a reddish color and usually appears only on iron objects.

Tarnish, on the other hand, can vary in appearance between metals. Tarnished silver is usually black, while tarnished copper gives your jewelry a green outer layer. Tarnish on most metals is not destructive since it sticks to the base metal and can act as a form of protection for the base metal as further oxygen and air can hardly touch the base metal.

What if My Gold Jewelry Rusts?

First, let me repeat the fact that real gold does not rust. However, I want to offer some possible explanations on the rare occasion that your gold jewelry rusts.

1. Fake

The risk of buying fake gold jewelry is always present, especially if you’re a beginner at buying jewelry. Although you can test the authenticity of your gold jewelry in several ways, seeing rust might indicate that it’s fake. The manufacturer might have made iron jewelry and painted or coated it with gold color.

Buying your gold jewelry from reputable brands would protect you from getting duped. Look for the hallmark on your jewelry; this mark signifies the base metal of the jewelry and its fineness level. You can also give professional jewelers to assess the jewelry for you or test it yourself using an XRF analyzer.

2. Iron Alloy

Jewelers never use 100% pure gold to create jewelry because the metal is too soft and malleable. Pure gold jewelry would easily bend, scratch, and lose shape; as a result, gold has to be alloyed with other metals. Mixing gold also reduces the price of gold jewelry and alters its appearance to create variations.

Jewelers can use any metal they desire to harden gold, and they mostly use copper, silver, zinc, and palladium. I’ve never heard of or seen any reputable jewelry brand that creates iron-alloyed gold jewelry. However, there’s a slim possibility that your gold jewelry might be alloyed with iron.

Jewelers don’t use iron as a gold alloy because it rusts. As previously noted, rust is a dangerous reaction to exposure and can completely destroy iron or iron-alloyed jewelry. When you think of how much we expose jewelry to moisture and air, you realize the disadvantage of iron in jewelry.

3. Plated Jewelry

Jewelry plating is an effective way of selling fake jewelry items as the real deal. It involves electroplating a cheap base metal with an expensive one. When correctly done, gold-plated jewelry looks like real gold; therefore, dubious jewelers use it to con people.

The plating doesn’t last forever, so your jewelry will begin to rust as the plating wears off. Gold plating acts as a protective shield for the iron jewelry; removing this shield exposes the iron to rust. Plated jewelry never wears off at once, so in this case, you’ll observe that the rust patterns only affect the unplated areas.

Read More: Does Real White Gold Tarnish?

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