Limestone

Limestone can only be mined at
 * the limestone quarry west of the Temple and River Salve and northeast of Varrock or
 * the white rocks near the Dire wolfs in northeast Tirannwn between the walled city of Prifddinas and road in Arandar.

It requires a mining level of 1 and gives 26.5 experience points.

It is required in the Regicide quest to make quicklime to make a barrel bomb.

Limestone can be crafted with a chiesel into limestone bricks which are used in the construction skill.