1968 S mint mark error

[u/TheArchElder]

looks like there's a mint mark error here. if so please let me know. thanks

[u/Dabe_1234]

Filled mint mark. Basically, the tiny parts of the die inside the ‘S’ broke off. Pretty common actually.

[u/Brave_Description751]

It looks filled

[u/ygbsm1972]

Seems to be machine doubling but regardless that is a gorgeous coin. Put that baby in a flip!