fur vs sable

fur and sable both are nouns.

Word	Noun	Adjective	Verb	Adverb
fur	Yes	No	No	No
sable	Yes	Yes	No	No

As nouns, sable is a hyponym of fur; that is, sable is a word with a more specific, narrower meaning than fur:

fur (noun)	sable (noun)
dense coat of fine silky hairs on mammals (e.g., cat or seal or weasel)	marten of northern Asian forests having luxuriant dark brown fur
a garment made of animal pelts or synthetic fur	a scarf (or trimming) made of sable
the dressed hairy coat of a mammal	an artist's brush made of sable hairs
	a very dark black
	the expensive dark brown fur of the marten

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