Neodymium Keychain Magnets for Testing Gold, Silver & Precious Metals

Discover the Power of Neodymium Keychain Magnets for Metal Testing

Quickly identify genuine gold, silver, and precious metals with this simple, powerful tool.

Neodymium keychain magnets offer a fast and reliable first-line test for authenticating jewelry and coins. Unlike ordinary magnets, these ultra-strong rare-earth magnets can detect even trace amounts of magnetic metals that indicate plating or counterfeits.

How It Works

The science is simple: genuine gold, silver, and platinum are non-magnetic. When you hold a neodymium magnet near these precious metals, there should be no attraction. If a piece claiming to be gold or silver sticks to the magnet, it contains iron, nickel, steel, or other magnetic metals—a clear sign it's either plated or not authentic.

What You Can Test

  • Jewelry: Quickly screen rings, necklaces, bracelets, and earrings before purchase or appraisal
  • Coins: Identify valuable silver and gold coins versus modern or counterfeit pieces
  • Collectibles: Verify the metal composition of antiques and precious metal items
  • Scrapping: Quickly separate steel, iron, and other ferrous (magnetic) metals from copper, stainless and other non-ferrous metals.

Quick Testing Guide

Simply hold the magnet about 1/2 to 1 inch from the item. No attraction means it could be genuine precious metal. Strong attraction indicates the presence of cheaper magnetic metals, suggesting the item is plated or counterfeit.

Important: While this magnet test is an excellent screening tool, it's not definitive. For valuable items, always seek professional authentication, check for hallmarks (like "925" for sterling silver or "14K" for gold), and consider additional testing methods.

The exceptional strength of neodymium magnets makes them far more effective than standard refrigerator magnets, catching subtle magnetic properties that weaker magnets would miss. Keep one on your keychain for convenient testing whenever you need it.

Choose the Right Keychain Magnet for Your Needs

Finding the perfect magnet for testing metals is all about balancing two things: magnetic strength (how powerfully it pulls on magnetic metals) and portability (how easy it is to carry with you). Here's how to choose:

21mm Magnet – The Best All-Around Choice ⭐

Large 21mm N52 Keychain Magnet Tester for Gold, Silver, Jewelry, & Scrap Metal - Envistia Mall

Size: About the diameter of a nickel (0.8 inches) and weighs 2 ounces. 

This is our most popular option and the one we recommend for most people. Think of it as the "Goldilocks" magnet—not too big, not too small, just right.

Why it works well: It's strong enough to give you a clear answer when testing jewelry or coins. If something contains magnetic metals (like iron or steel), this magnet will pull toward it noticeably. If it's genuine gold or silver, you won't feel any pull at all. The difference is easy to detect, even if you've never used a magnet for testing before.

Portability: Slips easily into a pocket, purse, or clips onto your keys without adding bulk. You'll barely notice it's there.

Best for: Everyday testing of jewelry, coins, and collectibles when you're shopping, at estate sales, or evaluating items at home.

28mm Magnet – Maximum Detection Power

Extra - Large 28mm N52 Keychain Magnet Tester for Gold, Silver, Jewelry, & Scrap Metal - Envistia Mall

Size: Just over 1 inch in diameter (slightly larger than a quarter) and weighs 4 ounces. 

This is the heavyweight champion—the strongest keychain magnet you can buy anywhere.

Why it works well: Some metals are only slightly magnetic, creating a very weak pull that smaller magnets might miss. This larger magnet has significantly more magnetic force, so it can detect even faint magnetic properties that indicate plating or mixed metals. If you're testing items where you need absolute certainty, or dealing with sophisticated counterfeits, this extra power matters.

Trade-off: Its larger size means it takes up more space in your pocket and has more weight. Some people find it a bit bulky and heavy for everyday carry.

Best for: Serious collectors, dealers, or anyone who needs the most sensitive testing possible and doesn't mind carrying a slightly larger tool.

12mm Magnet – Compact Convenience

Keychain Magnet Tester for Gold, Silver, Jewelry & Precious Metals With Rare Earth Neodymium Magnets 2 Pack - Envistia Mall

Size: About half an inch (roughly the size of a dime) and weighs less than 1 ounce. 

This is the pocket-friendly option that's always ready when you need it.

Why it works well: Despite its small size, it's still powerful enough for quick authenticity checks. It will easily tell you if a coin is made of steel (like certain wartime pennies) versus copper, or if that "silver" coin is actually magnetic (and therefore not real silver).

What to know: Because it's smaller, it has less magnetic force than the larger options. It works great for clear-cut cases (magnetic vs. non-magnetic), but might not detect very subtle magnetic properties in some mixed-metal items.

Best for: Quick spot-checks when you're out and about, or as a backup tester you can keep on your keychain without any bulk. Perfect for casual collectors or anyone who wants a testing tool that's truly pocket-sized.

How to Choose

  • New to metal testing? Start with the 21mm—it gives you reliable results and comfortable portability
  • Need maximum accuracy? Choose the 28mm for professional-grade detection
  • Want ultimate convenience? Go with the 12mm for effortless everyday carry

All three magnets use the same powerful neodymium technology—the difference is simply how much magnetic force they can generate based on their size.