we have these cement rings that are really popular for men at the gallery (here shown in its pink wax form). after being cast, the grooves are filled with cement and then polished as usual. Robin uses this same ring to create matching cuff links.
these ones are still not fully cleaned up. but after i saw them i thought they didn't really need the cement. i guess Robin thought so too, because the next time i was in the store i saw them in the case in this form.