melting pot vs crucible

melting pot and crucible both are nouns.

Word	Noun	Adjective	Verb	Adverb
melting pot	Yes	No	No	No
crucible	Yes	No	No	No

As nouns, melting pot and crucible are synonyms defined as:

melting pot and crucible: a vessel made of material that does not melt easily; used for high temperature chemical reactions

melting pot (noun)	crucible (noun)
a vessel made of material that does not melt easily; used for high temperature chemical reactions	a vessel made of material that does not melt easily; used for high temperature chemical reactions
an environment in which many ideas and races are socially assimilated