The passage is from the very end of the novel when the hero and heroine are leaving the island.
“Do we need to have identities in order to be together?”
“You mean from now on? Only if we want to be officially married.”
“Does it matter whether we are or not?”
“I don’t see why. But the one gold coin I managed to chip off could make us wedding rings, if you like.”
“You said it was fairy gold, and we’re not angels ..." Then, almost accusingly, "I didn’t know you’d managed to chip any gold off.”
“I wanted to surprise you. And I don't think the fairies will begrudge us just one coin out of it all.”