Need Middle Earth Adventure Idea

Not sure if I have the right board but I'll ask anyway....

I am running a quick AD&D 3e adventure tomorrow evening. I plan to drop the characters into Mirkwood. They are being chased by Goblins through the woods and find a cave that looks suitable to hide in. A dying elf is in that cave, having barely survived his venutre into the dungeon below the cave. I have a quick dungeon set for them where they retrieve a red gem shaped like a fist. I need an idea of what and why that gem exists and why the elf may have wanted it. My Middle Earth knowledge is limited to the Hobbit (for now - I am reading Tolkien daily now to learn more). So I would appreciate any help you might provide.

Thanks in advance.

Unfortunately I came back to visit Entmoot too late to give you any suggestions. But if you're still stumped and there will be another game session, I would say a reasonable scenario would be that the fist was shaped by evil dwarves from the east for Sauron, but when Sauron left Dol Guldur in 2063 he left it behind. Afterward, adventurers found the gem in the deserted fortress and took it north.

Of course, if the evil dwarves find out that someone has the gem, they might want it back....

Thanks. The session I had went well, so we are going to start a 3e campaign in Middle Earth. I have ordered via eBay some of the old Middle Earth products. Your suggestion is quite helpful. I can use it in a future session.

Again, thanks.

Glad to be of help.