Cymophane, better known as cat's eye, is the chatoyant variety of chrysoberyl: a translucent, usually yellowish stone in which countless fine needles of rutile, or tiny tube-shaped hollows, lie parallel and throw a single bright line across a polished dome. Its formal name comes from Greek words for wave and appearance. Dealers praise the finest stones as 'milk and honey', meaning a sharp milky streak over a honey-toned body, though lemon-yellow ones are liked as well. Quartz, tourmaline, corundum and other minerals can show the same effect, but Wikipedia says the jewellery trade keeps the bare name 'cat's eye' for chrysoberyl and gives the others a qualifier. It grew fashionable late in the nineteenth century after the Duke of Connaught gave an engagement ring set with one. Cunningham writes of 'cat's-eye' in a looser sense that he says usually means quartz holding asbestos fibres; he assigns it to Venus and earth and uses it for wealth, beauty, gambling, protection and healing, keeping it with money and wearing it set in silver. Hall describes it as a grounding stone that also stirs intuition, credits it with protection and confidence, and says its cymophane form steadies the intellect.