Pentamid

The RuneScape Wiki also has an article on: rsw:Pentamid

Pentamid
Released							4 January 2006 (Update)
Members							Yes
Quest item							No
Properties
Tradeable							No
Equipable							No
Stackable							No
Destroy							Drop
Examine							A red pentamid.
Values
Value							0 coins
Alchemy							Not alchemisable
Weight							0.001 kg
Advanced data
Item ID							6901

Pentamids are items used in the Enchanting Chamber in the Mage Training Arena. Like icosahedrons, cubes, and cylinders, they can be turned into orbs to obtain pizazz points in the minigame. If the player leaves the Enchanting Chamber, all pentamids will disappear from their inventory.