Jewelry was already established to be an important part of their culture, especially when it comes to families, and as it stands Kajaudi don't have traditional last names. I'm thinking about each family being tied to a particular stone or gem and having a sort of last name that means "of the [family's stone]".

This could also tie into the name of Kheii Jahl and Qariev's circus, which might be the Jewel Brothers Circus or just The Jewel Circus (haven't decided which yet). The jewel part is in direct relation to their family and culture without it being too clearly foreign that it turns away potential patrons (which is stupid and it shouldn't but land-dwellers are generally shitty toward Threllys/aquatic species and Qariev was smart enough to know that when he named the circus).