Counterfeit bullion is rare but real, especially silver. The good news is most fakes fail simple tests anyone can run at home with an inexpensive kit.
Visual Inspection
Real coins have crisp edges, sharp engraving and the correct weight stamping. Compare to a known authentic example. Common fake signs: blurry details, wrong color, soft edges, off-color reeded edges.
Weight and Dimensions
Buy a 0.01g jeweler's scale and digital caliper. Gold and silver have specific densities (gold 19.3 g/cm3, silver 10.5). A fake coin made of tungsten will be the right weight but wrong dimensions; a fake made of base metals will be the right dimensions but wrong weight.
Acid Test
An acid test kit (gold and silver versions) reveals fakes immediately by color change. Drop a tiny scratch of metal onto the test stone, apply the acid, watch the reaction. Damages only a tiny scratch.
Ultrasonic and Magnet Tests
Real silver and gold are not magnetic; if a coin sticks to a strong neodymium magnet, it is fake. For larger bars, a precious-metals verifier (about $300) uses ultrasonic to check density without any surface damage.
Gold & Silver Testing Acid Kit
From $18 on Amazon -- prices update in real time.
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