Yeah, you have to craft for the rings/necklaces. You can get most of the materials from the monsters; though they seem kinda uncommon. You can also harvest for crafting materials especially copper, bronze, and die stone.
It seems like it's not the material that's hard to get, but the low-lvl crafting stones that's made out of the die stones. ) :
SDGO NA - apricots
SDGO KR - tomatoes