lithomancer vs diviner

lithomancer and diviner both are nouns.

Word	Noun	Adjective	Verb	Adverb
lithomancer	Yes	No	No	No
diviner	Yes	No	No	No

As nouns, diviner is a hypernym of lithomancer; that is, diviner is a word with a broader meaning than lithomancer:

lithomancer: one who practices lithomancy
diviner: someone who claims to discover hidden knowledge with the aid of supernatural powers

lithomancer (noun)	diviner (noun)
one who practices lithomancy	someone who claims to discover hidden knowledge with the aid of supernatural powers