topaz vs transparent gem

topaz and transparent gem both are nouns.

Word	Noun	Adjective	Verb	Adverb
topaz	Yes	No	No	No
transparent gem	Yes	No	No	No

As nouns, transparent gem is a hypernym of topaz; that is, transparent gem is a word with a broader meaning than topaz:

topaz: a mineral (fluosilicate of aluminum) that occurs in crystals of various colors and is used as a gemstone
transparent gem: a gemstone having the property of transmitting light without serious diffusion

Other hypernyms of topaz include mineral.

topaz (noun)	transparent gem (noun)
a light brown the color of topaz	a gemstone having the property of transmitting light without serious diffusion
a mineral (fluosilicate of aluminum) that occurs in crystals of various colors and is used as a gemstone
a yellow quartz