jet black vs sable

jet black and sable both are nouns.

Word	Noun	Adjective	Verb	Adverb
jet black	Yes	No	No	No
sable	Yes	Yes	No	No

As nouns, jet black and sable are synonyms defined as:

Other synonyms of jet black include coal black, ebony, pitch black, soot black.

jet black (noun)	sable (noun)
a very dark black	marten of northern Asian forests having luxuriant dark brown fur
	a scarf (or trimming) made of sable
	an artist's brush made of sable hairs
	a very dark black
	the expensive dark brown fur of the marten

jet black (adjective)	sable (adjective)
	of a dark somewhat brownish black