Is Gold Magnetic? What the Magnet Test Can and Can't Tell You

The magnet is often the very first test a family tries on an inherited chain. It's free, it's harmless, and it takes a minute.

The short answer to the question is no: gold is not magnetic. But the magnet test is also the most misread test in the jewelry box. In this guide I'll show you how to use it properly, why a real gold chain can still twitch toward a magnet, and why "it didn't stick" proves much less than people think.

What a magnet really tells you

Gold, silver and copper are not magnetic. Neither is brass, one of the most common metals used to imitate gold. The metals a magnet pulls on are iron, nickel and cobalt, and steel, which is mostly iron.

That gives you one useful rule:

• A strong pull means there's iron, steel or nickel in the piece somewhere.
• No pull means only that there's no strongly magnetic metal in it. It does not mean gold.

Here's the nice part for you: the first half of that rule can save you a trip. A bracelet that leaps onto the magnet is not solid gold, whatever color it is.

The steel spring hiding in the clasp

Many clasps hide a small steel spring inside. That spring can make a perfectly real gold chain twitch toward a magnet, and more than one family has wrongly decided a chain was fake because of it. Brooch pins can be steel too.

So test each part on its own:

1. Use a strong magnet. A weak refrigerator magnet may miss a light pull.
2. Lay the piece flat on a folded towel.
3. Bring the magnet slowly toward it.
4. If anything moves, test the body, the clasp and any pin separately.
5. Write down "strong pull," "slight pull" or "no pull," and on which part.

If only the clasp reacts, you've learned something about the clasp, not about the chain.

Why "no pull" proves nothing

This is the most common mistake people make with a magnet. "If a magnet doesn't pick it up, it's real gold" gets repeated at kitchen tables everywhere, and it simply isn't true.

A brass bracelet with a thin gold plating won't stick. Neither will copper. Many gold-filled and gold-plated pieces are built on a base metal like brass, so the magnet passes right over them. The magnet also can't tell 10K from 18K: every karat of gold reacts the same way, which is to say not at all.

What the magnet can't tell you. It can't tell you that a piece is gold or silver, because brass, copper and many other base metals don't react either. It can't tell you the karat or the fineness. And it can't tell you whether a pull comes from the piece itself or from a hidden part, such as a steel spring or a brooch pin.

What to do after the magnet

Treat "it isn't magnetic" as a weak clue, in the same family as "it feels heavy" and "it's the right color." Stronger clues come from:

• The mark. Look for a quality mark, like 14K or 585, and check for letters such as GF, RGP or HGE, which mean layered gold. On American pieces made after 1961, the law asks for a trademark or maker's name beside the quality mark.
• A loupe. The FTC Guides note that plating isn't always the same thickness everywhere, and different surfaces wear differently. Look for a coppery, brassy or grey patch at edges, high points and clasps.
• A professional. Many jewelers and assay laboratories use X-ray fluorescence (XRF), which is usually non-destructive, though a heavy plating can affect it.

Please don't reach for an acid test kit at home. These kits use strong acids, including nitric acid, which the U.S. National Institute for Occupational Safety and Health says irritates the eyes and skin and can cause delayed fluid in the lungs. And an acid test can be fooled too: on a plated piece, the acid may meet only the gold on the surface.

When the strong clues agree, you can feel more confident. When they disagree, it's time for a jeweler.

Volume I, Real or Fake?, walks you through the loupe, magnet and density tests step by step and in the safe order, explains every common gold and silver mark, and shows you when to stop testing and hand a piece to a professional.