Perhaps a few guesses as to WHAT it is instead of "reading" the glyphs would help. The patterning and the obvious small size and it's artistic fine detail siggest it as a piece of statuary or fine pot to this observer. What would therefor appear as writing may be a repititious glyph-like pattern on the object.
Still it appears very ancient and worth intense study. Since it must have been a piece which pebble-like has tumbled in a stream it may be useful to go upstream in the river in which it was found, searching for wash downs of recent years which would uncover larger fragments or other artifacts.
Perhaps the finder would like to make a diligent search of the region or give someone with the time directions to it's exact location to pursue just as an archeologist would search for larger bone fragments. Analysis of the pot's clay source also comes to mind if it is indeed a potsherd.
Jack Lausa email@example.com