Precious Coin Tester User Manual

Precious coin tester is an application which helps to detect fake gold/silver coins. A user knocks the coin with another hard object (another coin, a pencil, etc.), and the app provides you the result.

How to use?

Run a test

  1. Open the app, select a coin from the catalog, or enter parameters for user-defined coins.
  2. Click on Check to start the analysis.
  3. While the progress bar is growing, hold the coin on the tip of one finger, and knock the coin briefly with another hard object near the mic of your phone/tablet.
  4. The coin generates its own sound after the knock. Hold still the coin while it rings.
  5. When the sound of the coin has diminished, knock it again. (Leave at least 1 second between to knocks)
  6. Repeat Step 5 until the progress bar finishes.

Please find also a longer video and check Common mistakes & Best practices for more details.

Read the result

The app uses three stars to indicate the quality of your coin:

  • ⭐⭐⭐: The coin passes the test (reserved for some coins selected from the catalog):
    • For silver coins (version 1.4.0 or above), the anticipated silver content does not fall more than 10% below the nominal value.
    • For gold coins (version 1.4.0 or above), the anticipated gold content does not fall more than 5% below the nominal value.
  • ⭐⭐: The coin passes the test: its sound matches that of a genuine coin, and its precious metal content closely approximates the nominal value.
    • 2/2: 3-star quantitative result is NOT available for this coin; this is the best result achievable.
    • 2/3: 3-star quantitative result is possible for this coin but was not achieved. This can also occur with genuine coins due to natural variations in the sounds of different specimens.
  • ⭐ (1/2 or 1/3): The coin probably fails the test. Its precious metal content likely differs from the nominal value, or its diameter and weight may differ from the nominal specifications.
  • 0/2 or 0/3: The coin fails the test.

Unstable result: Please test again as the sound quality is poor. We are not sure about the result.

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2 or 3 stars are positive results, indicating that the coin has passed the test successfully. On the other hand, results rated with 0 to 1 stars are deemed unsatisfactory, suggesting that the coin has failed or is likely to fail the test. All results provided are based on our best knowledge regarding those coins. It is important to note that they are for informational purposes only and do not come with any warranty or guarantee.

Sources of bad result?

Got a bad result? Let's find out why.

Maybe it is a false negative. There are 3 major reasons for this:

  1. Inaccurate parameters: this often happens with user-defined coins, or catalog coins without Verified mark (✔️). Please remeasure the coin, or double check the input parameters.
  2. Ping too frequently: pinging the coin too fast makes the app treat ping as background noise.
  3. Noisy environment: the app may wrongly treat environment noise as coin ping, although this rarely happens with our robust algorithm.
  • Another major reason is that the coin has a wrong purity, meaning that the coin is not a genuine one.

Please check Common mistakes & Best practices for more recommendations.

Replay the last test

You can reply the last test by clicking on the Replay button on the interface. The app will play you back the sound registered during the last test.

Limitations

Any tool has its limitations. Precious coin tester is not an exception.

  • It can be ONLY used to test round gold/silver coins without hole.
  • It can ONLY test the content of precious metal in the coin. The app cannot distinguish a fake coin of similar or the same percentage of precious metal from the real, original one.
  • Minimum fineness requirement: gold 7%, silver 20%; result might be inaccurate if gold < 20% or silver < 50%.

Interesting, but I don't have any silver/gold coin

You can also try the application with available videos. For example, in below video:

  • [1:47] Real silver eagle: got 3 stars from app
  • [1:59] Fake silver eagle: got 0 star unstable result from app
  • [6:52] 50 doller gold eagle (by guessing from image): got 2 stars from app

Since the quality of sound in videos is not as good as real tests, you may have frequently "unstable result". You can find more online test examples.