Drow Bolt

Drow Bolt +1 is an enchanted bolt +1, very similiar to normal bolt +1, except that this item turns into adamantine dust when its removed from the Underdark. It deals 1d8+1 points of damage and it has -1 bonus to THAC0. This item appears in Baldur's Gate II: Shadows of Amn and Baldur's Gate II: Enhanced Edition. It's dropped by drow archers.

In-game description
"Drow Bolt +1 Quarrels or bolts are the ammunition fired by crossbows regardless of the weapon's size. However this bolt has been imbued with a small amount of magical properties which enhances performance in flight, almost as if the bolt was guided towards its target. This item, like most drow equipment, is created using Adamantine, an alloy of adamantite that quickly turns to dust if removed from the Underdark."