Break The Mold Meaning

(idiomatic) To make it impossible for an identical copy to be made.

Example: 1997, Theodore R. Sizer, Horace's School: Redesigning the American High School, page 12:
  President Bush joined in; his 1991 education message called for new kinds of schools, ones that "broke the mold".
2001, Adam Troy Castro, Spiderman: Revenge of the Sinister Six:
  When they made him, they broke the mold. lt was a cliche that had been spoken about any number of men, for any number of different reasons.