quicksilver vs changeable

quicksilver is a noun but changeable is not a noun.

Word	Noun	Adjective	Verb	Adverb
quicksilver	Yes	Yes	No	No
changeable	No	Yes	No	No

quicksilver (noun)	changeable (noun)
a heavy silvery toxic univalent and bivalent metallic element; the only metal that is liquid at ordinary temperatures

quicksilver (adjective)	changeable (adjective)
liable to sudden unpredictable change	such that alteration is possible; having a marked tendency to change
	capable of or tending to change in form or quality or nature
	varying in color when seen in different lights or from different angles
	subject to change