An error coin can be explained as a coin which is not correctly struck during its manufacture. There are different types of error which are found on the coin such as off-struck center, coin with a wrong planchet type, number on the coin are not properly struck and many others problem which occurs during its manufacture.
Today we will discuss double stuck error coins. Such errors occur when a coin is struck again a coining die before it has left a coining press completely. This usually results in a partial impression of the coin over the previously struck image. The coin which is struck double times has a partial or full doubled image; such coin is known as double stuck coin, these coins have two identified image which is generally offset.
We can find the number of doubles struck coin, some of them can be major, minor or can be visible upon closer examination.
This copper 1/3 Falus issued by Ahmad Shah I of Bahamani Sultanate is an example of double struck coin. The reverse side of this coin is struck twice.
Image Courtesy: Todywalla Auction