scoria vs dross

scoria and dross both are nouns.

Word	Noun	Adjective	Verb	Adverb
scoria	Yes	No	No	No
dross	Yes	No	No	No

As nouns, scoria and dross are synonyms defined as:

scoria and dross: the scum formed by oxidation at the surface of molten metals

Other synonyms of scoria include slag.

scoria (noun)	dross (noun)
the scum formed by oxidation at the surface of molten metals	the scum formed by oxidation at the surface of molten metals
	worthless or dangerous material that should be removed