A Vulcan container designed to hold a katra, the living essence of a person, after death; one such ark was said to have preserved the mind of Surak himself.
A katric ark is a vessel in which Vulcans can store a katra, the essence or soul of an individual, once the body has died. By the 22nd century many Vulcans regard the katra as a myth, which makes the arks objects of faith as much as of technology.
The idea drives the Enterprise three-part story The Forge, Awakening and Kir'Shara. The dissident leader Syrran is believed to have found an ark holding the katra of Surak, founder of Vulcan logic, and to have taken it into his own mind. Dying in a sandfire storm in the Forge, he passes it to Jonathan Archer.
Guided by Surak's memories, Archer recovers the Kir'Shara, the original record of Surak's teachings, and the katra is later transferred to a Vulcan priest.