Vaidurya or Cat's Eye is the name given to the variety of chrysoberyl which beautifully displays chatoyancy, the phenomenon caused by the collection of needle-like rutile inclusions and the domed shape of the cabuchon cut. Cat's eyes are always cut in cabachons to emphasise the eye effect.
Vaidurya or Cat's Eye harmonizes Ketu which is traditionally known as the "tail of the dragon." In Jyotish, Ketu is the descending node of Chandra (Moon). Its influences are similar to Mangal or Mars and include liberation, abstract thinking, asceticism, non-attachment, healing, moksha (enlightenment), wisdom and that which is hidden.
Ketu's influence in the physiology is represented by the tail of the caudate. Its influence is over learning and emotions.