amulet vs good luck charm

amulet and good luck charm both are nouns.

Word	Noun	Adjective	Verb	Adverb
amulet	Yes	No	No	No
good luck charm	Yes	No	No	No

As nouns, good luck charm is a hypernym of amulet; that is, good luck charm is a word with a broader meaning than amulet:

amulet: a trinket or piece of jewelry usually hung about the neck and thought to be a magical protection against evil or disease
good luck charm: something believed to bring good luck

Other hypernyms of amulet include charm.

amulet (noun)	good luck charm (noun)
a trinket or piece of jewelry usually hung about the neck and thought to be a magical protection against evil or disease	something believed to bring good luck