Some Bicentennial quarters were minted in Philadelphia without a mint mark. These are relatively rare and can command a premium, especially in higher grades.
Bicentennial quarters with doubled die obverses, where the design elements are doubled due to a misalignment during the minting process, are highly sought after by collectors.
Proof sets containing Bicentennial quarters were also minted in 1976. These sets are often well-preserved and can be valuable to collectors.
In addition to regular proof sets, the U.S. Mint also produced silver-clad proof sets in 1976. These sets contain Bicentennial quarters made of 40% silver and are prized by collectors for their silver content and pristine condition.
Some Bicentennial quarters minted in San Francisco (S mint mark) and Denver (D mint mark) are worth collecting, particularly in uncirculated or proof condition.
While most Bicentennial quarters feature a drummer on the reverse side, there are variations in the design, such as the width of the drummer's drumstick and the positioning of the thirteen stars above him. Varieties with noticeable differences in design can be collectible.
Like other coins, Bicentennial quarters are subject to minting errors, such as off-center strikes, clipped planchets, and die cracks. Error coins are highly sought after by collectors due to their rarity and uniqueness.
Bicentennial quarters with low mintages, such as those from certain mint sets or special collector sets, are more desirable to collectors and can command higher prices.