horcrux

noun2

1. •
   In Harry Potter, an object in which a wizard has concealed a part of their soul through magic, rendering them immortal until the object is irreparably damaged or destroyed.

   • They stared at it as if it was the one ring or the holy grail or a horcrux, or perhaps all of them rolled into one. An empty, plastic cat food bowl. — 2013
2. •
   Something in which one has invested a part of one's self; an object which allows for the preservation of memory, culture, etc.

   • When I read manuscripts, I feel very aware that some part of the writer's soul lives in the pages—like a good Horcrux, say—and if I’m turning one down, I need to do so with thoughtfulness and respect. — 2016