Rock-crushing scrimshaw
The rock-crushing scrimshaw is an item that can be made with the Fletching skill at level 85 once all 4 scroll pieces of Rock Crushing have been obtained in the Player-owned port minigame.. The scrimshaw can be activated on and off for a total of 3 hours after which it degrades to dust.. 70 Mining is required to equip it. When activated, it increases critical hit chance while mining by 2%.