Tortoise shell

Tortoise shells are dropped by Tortoises and Warped tortoises. Both monsters can drop up to three shells at a time per kill. They can be sold to Barlak in Dorgesh-Kaan for 600 coins but sell for much higher on the GE. They are also used to make War tortoise pouches for Summoning thus making them highly valuable—war tortoise familiars are common familiars for high-level players to use, due to their ability to store 18 items and the fact that summoning them only requires 67 summoning.

Sometimes Tortoises and Warped tortoises can also drop Perfect shells, a rarer counterpart to the Tortoise shells. They cannot be used to make a War tortoise pouch, and like the regular version of the shells, a player may receive up to 3 of these shells. You can use them to get crafting experience in Dorgesh-Kaan. Perfect shells are untradeable.

Trivia

 * The tortoise shell was released a while before the release of Summoning and it had no use at that time.
 * On 19 January 2010 the tortoise shell was at a record high of price reaching a little over 16,000 coins, probably due to the demand of war tortoise pouches by players attemping Nomad's Requiem.
 * The price of the tortoise shell has been slowly decreasing after 19 January.