To get an initial indication of whether a gold item is pure, you can perform a simple test using a magnet. Pure gold is non-magnetic, which is a key property leveraged in this method.
Performing the Magnet Test
This quick check can help you identify potential impurities in a gold item you possess:
- Obtain a Magnet: Use a strong magnet, such as a rare-earth magnet, for the best results.
- Position the Magnet: Carefully place the magnet near the gold item.
- Observe the Reaction: Watch closely to see if the gold item is attracted to or repelled by the magnet.
Interpreting the Results
The interaction (or lack thereof) between the magnet and the item provides insight into its composition:
- No Attraction: If the gold item does not attract the magnet at all, it aligns with the property of pure gold (or very high purity gold alloys). This suggests the item is likely genuine gold with high purity, as pure gold is non-magnetic.
- Attraction: If the item is attracted to the magnet, it likely contains impurities. According to the reference: Pure gold is non-magnetic, so if the item is attracted to the magnet, it likely contains impurities, i.e., if the gold item is attracted to the magnet, it may indicate a lower purity level or the presence of ferromagnetic materials. This means the item likely contains other metals that are magnetic, such as iron, nickel, or cobalt, commonly used in gold alloys to increase hardness or change color.
Why This Test Works
Pure gold exhibits diamagnetic properties, meaning it is very weakly repelled by a magnetic field, but this effect is usually negligible and not noticeable with standard magnets. It does not attract magnets like ferromagnetic materials (iron, nickel, cobalt) do. Therefore, any significant attraction indicates the presence of these magnetic metals mixed with the gold, suggesting a lower purity level or that the item is not gold at all but made of a magnetic base metal with just a gold plating.
Limitations
While helpful, the magnet test is just an initial check. It cannot tell you the exact purity level (e.g., 24K, 18K) and some non-magnetic metals are also used in gold alloys (like copper or silver). For precise purity determination, professional testing methods are required.
