One of the most sought-after errors, the 1999-W Georgia quarter features a clipped planchet error, where a portion of the coin was missing due to a defect in the metal strip used during minting. This error is rare and highly valued by collectors due to its unique appearance and limited availability.
In the 2004-D Wisconsin quarter, an additional leaf was found on the corn stalk of some coins, known as the "Extra Leaf" variety. This error occurred due to a die modification, and while there are a few variations, the ones with the most distinct extra leaf are particularly valuable.
The 2005 Minnesota quarter features an “Extra Tree” error, where an additional tree was mistakenly added to the design on some quarters. This error resulted from a die defect and is highly prized among collectors for its rarity and the visual anomaly it presents.
In 2007, some Montana quarters were minted with an inverted “D” mintmark. This error happened due to the incorrect positioning of the mintmark die, making these quarters rare and valuable due to their unusual appearance and the small number of coins affected.
The 1999-P Pennsylvania quarter features a “Double Die Obverse” error, where the design on the obverse side of the coin is doubled due to a die misalignment. This type of error is valued by collectors for its distinctive appearance and the rarity of the error.
The 2000-P South Carolina quarter with a “Missing Clad Layer” error is notable because some coins were struck without one of the clad layers, resulting in a coin with a distinct, irregular surface. This error is particularly valuable due to its rarity and the striking difference from normal quarters.
Some 2002-P Ohio quarters were mistakenly struck without the “S” mintmark, which was intended for quarters produced at the San Francisco Mint. This error is valuable due to the rarity of finding an Ohio quarter without the expected mintmark, making it a coveted piece for collectors.