feldspar vs oligoclase

feldspar and oligoclase both are nouns.

Word	Noun	Adjective	Verb	Adverb
feldspar	Yes	No	No	No
oligoclase	Yes	No	No	No

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

feldspar: any of a group of hard crystalline minerals that consist of aluminum silicates of potassium or sodium or calcium or barium
oligoclase: any of a series of triclinic feldspars that form rocks

Other hyponyms of feldspar include orthoclase, plagioclase, moonstone.

feldspar (noun)	oligoclase (noun)
any of a group of hard crystalline minerals that consist of aluminum silicates of potassium or sodium or calcium or barium	any of a series of triclinic feldspars that form rocks