shell collecting vs conchology

shell collecting and conchology both are nouns.

Word	Noun	Adjective	Verb	Adverb
shell collecting	Yes	No	No	No
conchology	Yes	No	No	No

As nouns, shell collecting and conchology are synonyms defined as:

shell collecting and conchology: the collection and study of mollusc shells

shell collecting (noun)	conchology (noun)
the collection and study of mollusc shells	the collection and study of mollusc shells