It is common for coins to have imperfections in the composition of the metal alloy, although extreme cases are less frequent. These variations in the alloy’s composition can arise during the casting process in the foundry.
To obtain planchets that comply with the issue decree, it is essential to dose the different metals that make up the alloy in the correct proportions. If the metals are amalgamated in incorrect doses during the melting phase, several variations may occur. These variations include changes in the color, specific weight, magnetic attraction, and porosity of the alloy.