fossilization
noun /ˌfɒsəlaɪˈzeɪʃn/
  /ˌfɑːsələˈzeɪʃn/
(British English also fossilisation)
 [uncountable]- the process of becoming a fossil or of making something into a fossil
- Amber is a superb medium for the fossilization of fragile organisms.
 
 - (disapproving) the process of becoming, or of making somebody/something become, fixed and unable to change or develop
- the fossilization of the monarchy