oh this is a good question
ratio doesnt much like her bc he feels that shes too money-minded? but he likes talking to her about math, topaz is really good at math and has that knowledge actualized in terms ratio can speak with her about (vs aven who has an instinctive understanding of math and doesnt necessarily know the more mathematical terms). i think ratio and topaz have the most academic disagreements regarding economics in theory but in practice they can often find a way to meet in the middle. so ratio kinda likes her. they also have a competitive spirit and would get Rlly into it being on the same team in trivia nights. or with anything really. i think they also both watch sports together but only specific sports, theyre not sports bros but they have this sort of overly intellectual appreciation of it. they want to get statsbrained about sports. meanwhile aventurine's like "wanna bet on the winning team? lol" and they both scream at him.

topaz thinks ratio's far too...ivory-tower academic and wont stick around for him to tendentiously explain his principles to her. but she likes working w him and she likes that he can keep aventurine in check. there's a kind of mutual antipathy but reflexive teaming-up against aventurine b/w them :-)