Rotated die error State quarters were first discovered in May 1999 on the Pennsylvania quarters. Coin World reported the discovery to the numismatic community first. Soon afterward, other unsubstantiated reports began to value rotated die State Quarter errors at $500 – a price that was not based on an actual sale but on an estimate of similar errors on other coins sold years before. Coin World has received no reports about rotated die errors that have sold for $500.
Please note that some State Quarters errors are worth $500 and even $1,000 or more. These errors, however, are major striking errors that are extremely rare and are infrequently found in circulation. Those types of errors have been around for years on other coins, but they are especially sought on State quarters, which has driven their prices up considerably. To read about such errors, please read more about Striking Errors and Planchet Errors.
In reality the price for a 180 degree rotated State quarter in Mint State (Uncirculated) condition is in the $50 range, according to error coin dealers who have listed such coins on their fixed-price lists. A Mint State coin features no wear and very few marks or scratches. It certainly features no stains, unnatural toning or other discolorations.
The manner in which the errors were formed is easy to understand. Most U.S. coins have the obverse and reverse dies oriented so each side is upright when rotated vertically (end over end), at an alignment of 180 degrees. This type of orientation is called «coin turn.» Rotated dies occur when one die is not mounted properly in the coining press and therefore a coin struck by that die will feature one side out of alignment. The degree of rotation varies from 5 to 180 percent. History dictates that coins with greater rotations are worth more to collectors.
The Mint has yet to offer an explanation as to why these coins exist, because machinery and production procedures are supposed to be in place in the Mints (Philadelphia, Denver and San Francisco) to prevent such an error. There is also no way of knowing exactly how many of each rotated die error exists – there could be hundreds, there could be thousands. Some U.S. Mint presses can strike up to 730 coins per minute (yes, that’s 12 per second), and U.S. Mint dies are tough enough to strike 100,000 or more coins. Although coins are periodically spot-checked by technicians for flaws, errors still occur. However, the number of error coins that escape the Mint vs. the total number of coins produced is very, very small – a fraction of a percent.
Not all coin dealers specialize in error coins. Most error coin dealers have a broad base of customers who collect error coins and are therefore more likely to know how to properly identify and value error coins. If you are not an experienced coin collector, please note that a dealer’s buy price is lower than a list or retail price. If you sell your coin to an error dealer, he or she may not pay full retail price for the coin because he must turn around and sell the coin at the competitive retail price.