70's Christmas Napkin Rings - Christmas Dining - Poinsettia Christmas

This is a set of Christmas napkin rings. There are 4 Christmas bows, 2 poinsettia plants, and 1 is just white. They are marked "China" on the back, and I can't be certain but I think they might be porcelain. They just seem too. to be ceramic?? They measure approximately 6" on the outside circumference, and have a flat bottom so they sit nicely on the table. I'm guessing they're from the 70's. All are in very good condition. One has a small chip on its inner rim. As well, there are a few light marks on the back. Please see the pictures for details. Nothing too incredibly worrisome.