Carved keystone

The Carved keystone is a rock that has been chiseled into a bridge piece for Dungeoneering. It is used in a puzzle with a chisel and hammer, a broken bridge, and a Mining rock, which can be mined at various Mining levels to get a rock, which can then be chiseled at various Crafting levels into a keystone. The Carved keystone itself is a non-members item, but the ability to use it to repair the damaged bridge requires the Construction skill, which makes completing this puzzle members-only.