refractory pot vs bone-ash cup

refractory pot and bone-ash cup both are nouns.

Word	Noun	Adjective	Verb	Adverb
refractory pot	Yes	No	No	No
bone-ash cup	Yes	No	No	No

As nouns, refractory pot and bone-ash cup are synonyms defined as:

refractory pot and bone-ash cup: a small porous bowl made of bone ash used in assaying to separate precious metals from e.g. lead

Other synonyms of refractory pot include cupel.

refractory pot (noun)	bone-ash cup (noun)
a small porous bowl made of bone ash used in assaying to separate precious metals from e.g. lead	a small porous bowl made of bone ash used in assaying to separate precious metals from e.g. lead