The current America the Beautiful quarter series is known for poor-quality strikes caused by heavy die wear. But the poorness of this strike stands out.

Diminutive raised rings, semicircles, crescents, and spirals have bedeviled coin investigators for years. There has to be a reason, but what is it?

Error specialist Mike Diamond studies two very different-looking rim-restricted second strikes.

Wrong planchet errors can usually be traced back to the original purpose of the planchet or stock involved. "Orphans" can't be easily traced.

An overdate occurs when a date (or part of a date) is punched into a finished working die that already has an older date (usually that of the previous year).

Major horizontal misalignments of the anvil die are exceedingly rare. Even rarer are coins that display major horizontal misalignments of both dies.

Numerous past columns have recounted the various ways in which normally oriented incuse (or sunken) design elements can appear on a coin. Here's a new one.

Within a collector's newest batch of 2016 Lincoln cents, one coin stood out among all the others. There are two reasons why.

When the collar (the retaining ring that establishes the final diameter of a newly-struck coin) experiences brittle failure, several collar breaks may result.

A collar break is expected to appear in the same spot on the edge of every coin struck within that collar. The 2002-P half dollar defies that expectation.