Fictional Class Rings

As I was laying in bed last night supposed to be asleep, I was instead thinking about Starfleet. Mostly the Starfleet Academy. I started to wonder if they made Starfleet Academy class rings -- I know Starfleet is fictional. I still wondered. Looking around I discovered the answer was no, not really. There is the one available at Thinkgeek that only comes in size 10.5, there are a few actual props from TNG floating around for a million dollars, and I found another made in China which at least comes as small as a size 7... but nothing really customizable. For instance adding Ex Astri, Scientia; a name; a stardate; perhaps even customizing the gem to coordinate with your division, and so on.

So I went to the typical companies one goes to when having a class ring made only to discover most of them (Jostens, Balfour, etc.) only allow for actual schools that exist. Like, you cannot customize them without first inputting your school name, city, and state. If it doesn't recognize the school you entered, such as Starfleet Academy, you can't proceed. I discovered one site that did and wound up spending like 30 minutes customizing a Starfleet Academy class ring. I'd never buy it for myself, because it'd cost like $120, but it was fun to play around with.

Then I got to wondering though, would there be a market for this? Now that being a nerd about something isn't a giant social stigma you'd think companies would capitalize on it, but they've yet to do so. Would it be illegal for me (or anyone unaffiliated really) to profit from this sort of market?

Like, were I to make Starfleet and Hogwarts class rings and sell them, would that be copyright infringement? I'm not considering it seriously, obviously, but it makes me wonder. Were I Urban Outfitters I'd probably be fine, of course, but as just a sole entity would this be acceptable?