Well, the sea glass candy turned out pretty well! Above is a picture of the peppermint and cinnamon all mixed up in the tin we used.
The whole process is easier than I thought it would be, although our first batch didn't boil evenly and was therefore stickier and less brittle than we were hoping for. For the second batch, though, we were more careful and the candy cracked easily when it was done.
The final step - painting powdered sugar on the candy to give it that dull sea glass look - is fun, but very time consuming. I'll have to think about whether we still want to do this for the wedding. Maybe we could make a bunch and have our wedding parties over for a candy sugaring party!