Seashell Clasp Bracelets

Here we have a couple of vintage seashell clasp bracelets. I made both of these out of some materials I got some years ago in an old estate sale. I have no way of telling how old they are, but I wanted to finally make something out of them. I have two kinds, seashell chips and rounds. I am unsure what species of animal the rounds come from. They are different sizes:

Chips: 7 - 8 1/2in
Rounds: 7 - 9in

If you have a smaller ankle, the rounds one can also be used as an anklet.