Strange rock

The Strange rock is an item from the Shattered Heart Distraction and Diversion. It may be found randomly while training any non-combat skill. Players may get two strange rocks per skill. The first rock is found fairly quickly, but the second rock usually takes longer to find. Each strange rock is a segment of the statue of Dahmaroc, a wizard from the second age.

After using both on a Statue plinth, the player gets $$y = (x)(x-1) + (100-x)$$ where $$y$$ = Experience earned and $$x$$ = Skill level of the skill being trained when the rock was received. The player needs two rocks from each skill to complete the statue. When the player has collected two pieces in one skill, they can be added to the Plinth in order to create a section of the Dahmaroc statue. The Plinth is located in the Varrock Museum right next to the entrance. The rocks are not stackable in the bank, however. You can identify what skill a strange rock is from by examining it. Strange rocks will not appear under a players gravestone when they die. Strange stones can be gotten every load if woodcutting etc

Skills
Players will receive strange rocks while training non-combat skills. Strange rocks can be found while training the following skills:
 * Agility
 * Herblore
 * Thieving
 * Crafting
 * Runecrafting
 * Mining
 * Smithing
 * Fishing
 * Cooking
 * Firemaking
 * Woodcutting
 * Fletching
 * Farming
 * Hunter
 * Construction