The Scar on Sophie's Face

The scar symbolizes the brutality Sophie faced from her former employer, and it greatly affects how she feels about herself.

The Book of White

This book symbolizes Mortmain's continued efforts to create clockwork people that can think and reason though the use of a binding spell. The book was stolen from an Institute and Mmortmain's adopted parents were punished for the theft.

The Clockwork Angel

This is Tessa's necklace and it symbolizes a connection with her mother and hints at a connection with her power, though that connection is not yet clear. Most of the time, the angel is still though Tessa can hear it ticking, like a clock. When the clockwork people are about to grab Tessa, the angel comes to life, saving her.

Yin Fen

Jem is addicted to this drug, which symbolizes the lack of control a person has...