Limestone

Limestone can be mined by a player with a Mining level of 1, and gives 26.5 Mining experience when mined. Limestone can be crafted into limestone bricks through the Crafting skill, although it may accidentally become a rock. It is required in the Regicide quest to make quicklime to make a barrel bomb. It's also used in Construction. Limestone can also be purchased from the builders/general store in Mort'ton for 10 coins. There are only two locations at which it can be mined:
 * the limestone quarry west of the temple Paterdomus and northeast of Varrock
 * the white rocks near the dire wolves in northeast Tirannwn between the walled city of Prifddinas and road in Arandar.

Attempting to smelt the limestone will inflict 8 points of damage.

Examine text
For "Pile of Rock": For "Limestone":
 * Prospect - "This rock contains limestone."
 * Examine - "A pile of lime rock."
 * Examine - "Some limestone."