Fake double-struck error coins on eBay
In the course of researching double-struck errors, I've found a number of fakes appearing recently on eBay.
On genuine double-struck coins, the first strike is weaker, having been flattened or distorted to some degree by the second strike. On the recent batch of fakes, in contrast, the weaker strike is actually the second strike (made with a counterfeit die) and, while weak, is not flattened, since it has not been overstruck.
Another common feature on this group of fakes is that only one side of the coin is double-struck. A genuine one-sided double-strike can occur when a coin is struck twice in collar without rotation, but one of the dies rotates between strikes. This normally occurs on proof coins, however, which (at least during some periods) were struck twice as a matter of routine. It is rare to see this occur on business strikes, so when many such business strike coins are offered in succession by the same seller, it is a red flag.
The fake double-struck coins have fooled consumers, such that some of them have sold recently on eBay for hundreds of dollars. They may at times be marketed as doubled dies, rather than double-struck. Here is one such fake that has already been reported and removed:
It appears that the second (counterfeit) strike was at an oblique angle on this example; consequently, major areas of the design are missing.