odd little 'clear sphere' bracelet (?)

This is a strange little one, probably a (charm?) bracelet by its size, roughly 9" length. It is made of small pearl-escent beads each on individual wires looped together, the wires are copper or brass (a yellow toned metal anyway) which has tarnished/corroded slightly greenish. Its little catch is goldtone, and its feature is a clear acrylic plastic (??, it doesn't seem heavy enough for glass) sphere about 5/8" across, held captive in a goldtone hoop dangling from the bead chain by a jump ring. I cannot see any evidence of a seam on or an opening into the sphere, if either is there it is well hidden within the hoop.

That sphere is the weird part -- it is NOT solid, as what appears as a tiny little spot on it (in pics 3 & 4) is actually a LOOSE little bit of something *inside* the sphere, capable of moving around in there. Presuming there's also some magnification going on due to the shape, I can't guess how small that little bit might really be. There are no markings whatsoever on it.

Part of me wonders if it could be some variety of "religious icon" remnant of something (or somebody?) but if so I'd think there *would* be some markings or symbolism on it??? Clues WELCOMED if anybody here has seen something like it and can share any more info!!