Double-Die Obverse Quarter: This coin has a significant minting error where the die used was misaligned, creating a visible double image.
Full Drum Lines Quarter: A quarter featuring sharp and complete drum lines on the reverse design is rare, as these details are often worn down.
San Francisco Mint Proof Error Quarter: Proof quarters from the San Francisco Mint, especially those with noticeable errors like misaligned dies or doubling, can fetch up to $160,000.
No S Mintmark Quarter: A proof Bicentennial quarter struck without the 'S' mintmark from the San Francisco Mint can be valued over $150,000.
Silver Composition Error Quarter: Some Bicentennial quarters were mistakenly struck on a silver planchet instead of the standard copper-nickel.
Off-Center Strike Quarter: Coins struck off-center but still retaining visible essential elements are prized for their visual uniqueness and rarity, driving their value significantly