feldspar vs orthoclase

feldspar and orthoclase both are nouns.

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

As nouns, orthoclase is a hyponym of feldspar; that is, orthoclase 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
orthoclase: a white or colored monoclinic feldspar

Other hyponyms of feldspar include oligoclase, plagioclase, moonstone.

feldspar (noun)	orthoclase (noun)
any of a group of hard crystalline minerals that consist of aluminum silicates of potassium or sodium or calcium or barium	a white or colored monoclinic feldspar