sable vs jet black

sable and jet black both are nouns.

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

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

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

sable (noun)	jet black (noun)
marten of northern Asian forests having luxuriant dark brown fur	a very dark black
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

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