I think it looks like a bail for a gemstone donut. The more pointed end should open so you can put a gemstone donut in, and hang it by the smaller loop on a cord.
I tried opening it,and it does open. However when It was given to me it was strung on a necklace by itself with no pendant attached,and my friend purchased it that way,So I'am figuring it could be used as both. which is wonderful,cause versatility is key when designing and creating jewelry pieces :)