Indian astrology defines nine stones for nine planets. These nine gemstones are called Navaratna or Navratna. Ketu is the ninth planet and Cat's eye is the stone for that planet. Cat's eye is a mysterious gemstone having a silver lining. It belongs to Crysoberyl group and is a precious stone.
View this article about Cat's eye gemstone.
(Vardhaman Gems, Jaipur represents Centuries Old Tradition of Excellence in Gems and Jewelry)