I spotted a small rune amulet / pendant on the path up to Moel Famau on Saturday 29th June 2013. It looks like someone had already picked it up and placed it carefully on a flat stone to one side of the path.
I left it there in case the owner came back, but just in case, I think the location was:
South of the summit / Jubilee Tower.
Perhaps around 500 metres from the top.
On the less steep of the two ‘purple routes’ from Coed Moel Famau car park, i.e. the path that loops west of the steeper shale path up to the top.
On a rock on the left hand side of the path as you ascend.