Delaware Spitting Horse Error: This error on the Delaware state quarter shows a line extending from the horse's mouth, making it appear as if the horse is spitting. This die crack error is highly sought after by collectors.
Minnesota Double Die Reverse: On the Minnesota state quarter, look for extra trees near the large tree on the right side of the design. This doubling error can vary in appearance, making some versions more valuable.
Kansas "In God We Rust" Error: This error occurs on Kansas state quarters where the "T" in "Trust" is partially or completely missing, making it appear as "In God We Rust." This minting mistake is popular among collectors.
Wisconsin Extra Leaf Error: The Wisconsin state quarter has two major varieties with an extra leaf near the corn ear – a "high leaf" and a "low leaf." Both varieties are valuable due to their rarity.
New Hampshire "Humpback" Error: This error shows a noticeable hump on the back of the Old Man of the Mountain on the New Hampshire state quarter. The deformity is caused by a die crack and is highly collectible.
South Carolina Die Crack Errors: Some South Carolina quarters have die cracks that appear as lines extending from various elements of the design, such as the palmetto tree or the outline of the state. These errors are less common and can add value to the coin.
Connecticut Double Die Obverse: The Connecticut state quarter has a known double die obverse error, where elements of the obverse design, such as the tree branches, appear doubled. This error is rare and valuable to collectors.