Closer to avian behaviour than other lizards, the krayt dragon swallows stones to aid in digestion. Occasionally, these stones, which never get regurgitated, are semi-precious or precious in nature. Over time, some of these rare minerals get refined into perfect spheres; though more often than not, they are ground into powder and excreted with the rest of the lizard's waste.
Stones that withstand the constant grinding actions in the krayt draon's gizzard become one of the rarest objects in the galaxy, a krayt dragon pearl. These stones, ranging in size from a few millimetres to up to five centimetres, are invariably polished to a lustrous state, and depending on the type of stone that was ingested, are often hued in shades of white, black, blue or green. Rumours of larger sizes and other colours exist, but positive evidence of either has yet to be produced.
Due to the fact that the pearls can only be extracted from a dead krayt dragon, these gems are considered by many peoples to be a mark of bravery and courage since fighting a krayt dragon to the death and removing the pearls from its gizzard is a daunting task for anyone. Some sources claim that the Sand People favour those that hold pearl trophies, but this has not been sufficiently proven.
It is said by certain Jedi that the most perfect of krayt dragon pearls can, with the proper skills and preparations, be used in place of the crystal in the construction of a lightsaber. While the unique refractive quality of these pearls certainly makes it possible to do this, the installation process is extremely difficult and the price for those who would rather choose to avoid battling a dragon for this prize is extraordinarily prohibitive. Often, a single pearl can fetch hundreds of thousands of credits on the market.