Calcelmo's Stone Rubbing

 is a quest item used in Hard Answers. It is created by the player picking up a Roll of Paper and Charcoal and activating Calcelmo's Stone in the tower of Calcelmo's Laboratory, whereupon the item appears in the player's inventory.

Bugs

 * After completing the quest, it is possible to find this item on the floor inside the halls at the College of Winterhold. Once picked up, the item may trigger the quest again. Alternatively, it may just be stuck in your inventory marked as a quest item.
 * To fix this, open the console and enter 'player.drop 00033764 1' to remove it from your inventory.