Numismatic News reader David Hiddleson of Iowa sent in a very nice example of a 2000-P Sacagawea dollar with a Strike-Through error. In this case the coin is struck through what I like to call “Mint Goop.”
Debris, (which can build up around machinery), made up of grease, oil, metal filings, etc., may work itself into and cover the dies. When this occurs it can fill certain areas of design and prevent those areas from being struck up on the coins the dies are striking.
In this case we can see that the obverse was the recipient of most of this activity and that the areas closest to the rim where the goop first enters the dies is the most affected. IN and WE of IN GOD WE TRUST, the entire word LIBERTY that is normally positioned about the upper rim and the final “0” of the date are missing. We can also see that the goop oozed in even further to affect major areas of the central design.
The reverse got covered with a thin layer near the rim affecting portions of some of the letters closest to the rim but not too dramatically. Other than that, the reverse is very well struck.
Filled die errors (which these are often called) range from minor examples to majors with values ranging from just a few cents over face value to hundreds of dollars, depending in the severity and coin type effected. Generally, ones like this are considered fairly major.
While we are on the topic of Strike- Through errors we might just as well look at a few others that do not involve mint goop. Suzanne Stewart of Virginia sent in several examples.
Another type of Strike-Through error that we see a lot of are the Struck-Through-Lint errors found on proof coins. Because the dies used to strike proof coins are routinely wiped clean with a rag from time to time, there is an opportunity for lint to be left behind on the dies.
This is what happened with both her 2008-S clad Hawaiian quarter and her 1999-S clad proof Kennedy half. These are generally minor and do not attract much attention from error collectors, but are nonetheless, fun to find.
A note of caution: this type of error does not add value to a scarcer date proof coin. It actually can detract from its value. For example, if this 1999-S half was of the more valuable silver version, many folks would avoid buying it at full value and it might only be able to be sold at a discount.
Stewart’s final coin is a 2006-P South Dakota state quarter with matte finish from out of the government issued Mint Set. It shows at least four noticeable flecks of copper struck into the surface of the reverse. These copper flecks may have fallen away from struck coins that had finning on them as was described in my March 17 Numismatic News article, “Dime struck through reeding.”
Whatever the source of the copper flecks, the end result is very interesting and undoubtedly adds some value to the coin as an error.
Ken Potter is the official attributer of world doubled dies for the Combined Organizations of Numismatic Error Collectors of America and for the National Collectors Association of Die Doubling. He also privately lists other collectible variety types on both U.S. and world coins in the Variety Coin Register. He is a regular columnist in Numismatic News’ sister publication, World Coin News, where he writes the Visiting Varieties column. More information on either of the clubs or how to get a coin listed in the Variety Coin Register may be obtained by sending a long, self-addressed envelope with 60 cents postage to P.O. Box 760232, Lathrup Village, MI 48076, or by contacting him via e-mail at KPotter256@aol.com. An educational image gallery may be viewed on his Web site at www.koinpro.com.