bone char vs bone black

bone char and bone black both are nouns.

Word	Noun	Adjective	Verb	Adverb
bone char	Yes	No	No	No
bone black	Yes	No	No	No

As nouns, bone char and bone black are synonyms defined as:

bone char and bone black: black substance containing char in the form of carbonized bone; used as a black pigment

Other synonyms of bone char include animal black, animal charcoal.

bone char (noun)	bone black (noun)
black substance containing char in the form of carbonized bone; used as a black pigment	black substance containing char in the form of carbonized bone; used as a black pigment