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Coin authenticity verification

Touch, visual and comparison tests are recommended to check the authenticity of coins

1. Touch test

When touching a coin you should notice:

  • The assembly. In the case of bimetallic coins, the assembly of the peripheral ring is almost perfect, making the frontier between the two parts hardly noticeable to touch.

 

  • Edge. This can be smooth, grooved (a series of parallel slots on the edge of the coin), unevenly grooved (a combination of parallel slots and smooth slots) or peripherally marked. If there are burrs or other irregularities it could be a counterfeit coin.

  • Texture. A coin should be smooth. If it feels slippery or soapy, it could be laminated and therefore counterfeit.

2. Visual test

Features that can be identified at sight:

  • The color. Color is a unique characteristic of each coin. The color is produced by the melting of two or more metals (a process called alloy) during minting. The color is set when the metals are melted and does not change during the life of the coin. Mexican coins are not covered with anything, nor do they have metal plate or painting on the surface; therefore they do not become discolored.

 

  • Brightness. This is obtained during minting and like color is a characteristic of each alloy.

 

  • Smoothness. Parts of the coin that are not engraved should be smooth, even and without porosity.

 

  • Wear and tear. Because coins are used daily they undergo a natural and irregular (uneven) process of wear and tear. If a coin has regular or homogeneous (regular) wear and tear, or the overall engraving is not sharp, it could be counterfeit.

3. Comparison test

  • If you have any doubts about the authenticity of a coin, compare its weight, diameter and thickness with another you are sure is authentic.  Any noticeable difference in the weight, diameter or thickness could mean the coin is counterfeit.