Hi Christine! That's an interesting bead. Here is a small Islamic(14mm) on which the glass has deteriorated over part of the bead, and on that portion it looks very much like stone. The third pic is of one of my favorite stratified-eye beads(19mm) that I don't know the age of (I've only seen one other similar to it), but many of the eye layers look like stone to me. It was my first impression of the bead, besides loving it! Steve