Afaik, items operate by name.
Name anything in your inventory "Adamantium Ore" (or whatever it was called, "Adamantium Ore Nugget" - I honestly don't remember) and try to talk to her. You may also have to set it as a "Miscellaneous" item.
Just like how you can take any armour pieces and put "Bronze" in their names in order to qualify for solving the bronze riddle.
This is all really easy on the PC, with the editor, but I honestly have no idea how you'd solve this on a Mac.