Thank you for your comment.

I'm more positive about the idea that original bead is from ""West Asian "Islamic" and probably Byzantine eye beads"" than Jatim.

The diameter is approximately 21mm.
The size is smaller than normal Jatim.
And it's each mosaics are also small and fine detaile more than Jatim.

The long bead with same kind of mosaic was found in east Java but I believe it's from outside of Java.

I think the quality of mosaics of turtle are more close to mosaics of the long bead below than Jatim I posted before.