This is a Eisenhower dollar type-2 blank (no upset rim, but annealed and polished.) The blank has very unusual proof-like surfaces which are far different from a normal Ike dollar blank. The surfaces are highly polished and mirrored. This coin was part of the San Francisco Hoard of planchets/blanks, and many of those were rare proof and experimental planchets. This blank was undoubtedly an experimental or proof blank, and as such is rare.
NGC certified but not graded. Nice eye-appeal.