Sometimes the best nontraditional engagement ring isn’t a ring at all; one Indiebride poster’s fiancé proposed with a skee-ball machine. If your sweetie’s not a skee-ball champ, though, you can always go with one of the following options, or pick a design from The Carrot Box, a blog devoted to unusual rings.

1. These wooden rings are simple and environmentally friendly.

2. A silver ring inlaid with poured concrete—yes, concrete—is perfect for Bob-the-Builder types.

3. These acrylic cube rings from Japan put a ‘60s twist on the meta-ring concept.

4. Geeks who don’t mind spending a little more money can immortalize their love in binary code.

5. Some antique stones might be "blood diamonds," but at least they’re recycled. Try the lovely art deco rings at Circa1930s.