The Wheel of Time - The Call of the Horn
Sa’angreal (pronounced: SAH-ahn-GREE-ahl) are similar to angreal in that they allow channelers to use more of the One Power than they could otherwise safely access. Lots more. All sa’angreal multiply exponentially the amount of the Power upon which the channeler may draw; probably as a consequence, they are much rarer even than ordinary angreal. Most angreal and sa’angreal are constructed with a buffer to protect the user from drawing too much of the Power. One male sa’angreal in particular, Callandor, is known to lack this buffer, why is not yet fully understood. In order to overcome the danger of drawing too much Power with Callandor, two women must be linked to one man, with one of the women guiding the flows of saidin. All known examples are either usable by a woman for channeling saidar or a man for channeling saidin; whether it is possible to make a sa’angreal that can help with both is unknown.
List of Sa’angreal
A wand made out of a bone-like material, housed in the White Tower; used to Heal Mat Cauthon from holding the Shadar Logoth dagger and later by Egwene in the Battle of Tar Valon. It is referred to as Vora’s sa’angreal by Adelorna Bastine.
The Choedan Kal; A very large statue of a woman holding a crystal ball, half buried on the island of Tremalking. It is the most powerful sa’angreal ever made, along with its corresponding male counterpart. It is controlled with a ter’angreal called an access key, which is needed so that the channeler may survive the massive amount of the Power available by the Choedan Kal. (The female Choedan Kal was destroyed in the cleansing of saidin.)
Callandor: a sword that appears to be made from glass, but can cut like any other. Sometimes called the “Sword That Cannot Be Touched” or the “Sword That Is Not a Sword.”
The Choedan Kal: A very large statue of a man holding a crystal ball, half buried in a village of Tremonsien in Cairhien. It is the most powerful sa’angreal ever made, along with its female counterpart. It is controlled with a ter’angreal called an access key, which is needed so that the channeler may survive the massive amount of the Power available through the Choedan Kal. (The male Choedan Kal was destroyed by Rand atop Dragonmount.)