Not a stupid question. It happens to me a lot as well. What I do is
1. Check the whole area (around the Gidbinn activating thing). It creates a little monster who drops it and he is very dark and almost transparent. Not easy to see.
2. Leave the area and come back.
To leave the area it can be going down into the dungeon there or run out into the forest. Or TP to town as a last resort.
If that fails you might need to make a new game but it's only the Gidbinn. Not a very important quest really.