Gem of Damage Modification

From the Clutch of Kings quest introduced in the On Bended Knee event.

Gem of Damage Modification
Value: 0 10 Burden Units
This gem can be added to the Burun slaying variant of the noble atlatl, bow or crossbow. If so, it will enhance weapons [sic] damage modification. The weapon will then only be wieldable by the crafter. Combine with a Burun Slaying Noble missile weapon to enhance the damage modifier of the weapon. This item cannot be sold.