Lamination errors
This type of error occurs when foreign bodies or impurities (metal dust, slag, debris, etc ...) are trapped inside the metal which is melted and transformed into ingots for the production of new planchets. These foreign bodies will then be part of the planchets and subsequently of the coins produced with those planchets. In the production of the planchets, if foreign bodies were present in the metal, they would tend to peel off. These metal losses can occur before or after minting due to the presence of contaminants in the alloy. This phenomenon can also occur when the planchets are composed of several layers.
In extreme cases, the planchet can split into two distinct sections forming two circular planchets of lesser thickness, called “split planchet”.
A split planchet before strike will have streaks on the face involved in the separation. The texture of the streaks varies from coarse to fine. If a keystroke is unusually strong, most of the streaks fade away. A coin struck on a split planchet before strike will always weigh less than a normal coin. However, most of these split coin planchets before strike show weak beating, as the planchet is thinner.
In the case of split coin planchet after strike, the side involved in the separation will have streaks on the face involved in the separation. Furthermore, it will present a spectrum in incuse and in regular position of the embossed reliefs on the opposite side of the coin (the one not involved in the separation).
This kind of error is sometimes erroneously referred to as uniface. It cannot be designated in this way because in reality, as mentioned above, the planchet is minted correctly on both sides and the separation takes place after the minting.
On the following page, we can admire a magnificent complete split coin planchet after strike (pair from the same coin) from the same collection, separated into two distinct sections after minting. It is possible to find a complete split coin planchet, even if it is really very difficult.
Use the keyword lamination errors in the global search engine to view all the coins with this type of error.
Log in or Subscribe to enter new coins in the search engine. Do you want to know the prices and rarity of all the coins in our database? Buy now a premium subscription discounted at 50% of the price until 12/31/2022.
For info, estimates and certificates of authenticity visit Senacoins.com