I have a character in a story I'm writing who wears a necklace with a 'thing' on it. It is the piece of a necklace that’s not the chain. I want to state it is a pendant or charm, but that is not the word I'm thinking of.

This item was carved out of wood by her father. It has a cross on one side and a trilogy symbol on the other side. It is a bit clunky being that it is only slightly more massive than a safety deposit key (a small one). It is also perfectly circular, if that matters. What would this piece of jewelry be called?

Answer:
Amulets have special powers. I'd say that what you have is a medallion (even if it is made out of wood, it sounds like it's about the size/shape of a coin).
Answer:
amulet, talisman, charm?
Answer:
an amulet.
Answer:
medallion?
Answer:
an amulent or however its spelled?