fragment vs spall

fragment and spall both are nouns.

Word	Noun	Adjective	Verb	Adverb
fragment	Yes	No	Yes	No
spall	Yes	No	No	No

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

fragment: a piece broken off or cut off of something else
spall: a fragment broken off from the edge or face of stone or ore and having at least one thin edge

fragment (noun)	spall (noun)
a broken piece of a brittle artifact	a fragment broken off from the edge or face of stone or ore and having at least one thin edge
an incomplete piece
a piece broken off or cut off of something else

fragment (verb)	spall (verb)
break or cause to break into pieces