chert vs taconite

chert and taconite both are nouns.

Word	Noun	Adjective	Verb	Adverb
chert	Yes	No	No	No
taconite	Yes	No	No	No

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

chert: variety of silica containing microcrystalline quartz
taconite: a variety of chert containing magnetite and hematite; mined as a low-grade iron ore

chert (noun)	taconite (noun)
variety of silica containing microcrystalline quartz	a variety of chert containing magnetite and hematite; mined as a low-grade iron ore