Of all the Chinese works on jade the most interesting and remarkable is the _Ku yü t’ou pu_ or “Illustrated Description of Ancient Jade,” a catalogue divided into a hundred books and embellished with upward of seven hundred figures. It was published in 1176, and lists the magnificent collection of jade objects belonging to the first emperor of the Southern Sung dynasty. One of the treasures here described was a four-sided plaque of pure white jade over two feet in height and breadth, and it was regarded as of altogether exceptional value, for on it was a design miraculously engraven. This was a figure, seated on a mat, with a flower-vase on its left and an alms-bowl on the right, in the midst of rocks enveloped in clouds. The figure was an image of the Buddhist saint, Samantabahadra, and the plaque is said to have been washed out of a sacred cave in the year 1068, by a violent and mysterious current.[370] Jade talismans are very popular at the present day in the Mohammedan world, and among the Turks they are so highly prized as heirlooms that it is difficult to secure any of them. There is an orthodox Mohammedan sect, whose members call themselves Pekdash, and who during their whole lifetime carry about with them a flat piece of jade as a protection against injury or annoyance of every kind.[371] The four rain-making gods are shown wearing necklaces of coral and turquoise in the ceremonial sand-paintings of the Navajos. These four gods are respectively colored to denote the four cardinal points; black for North, blue for South, yellow for West, and white for East. The whole painting, measuring nine by thirteen feet, is guarded on three sides by magic wands; toward the East it is left unprotected, as only good spirits are believed to dwell in this direction. Each of the rain-gods carries suspended from his right wrist an elaborately decorated tobacco pouch, bearing the figure of a stone pipe. The Navajos believe that in this pouch the god places a ray of sunlight with which he lights his pipe; when he smokes, clouds form in the sky and the rain descends. In the sand-picture representing the God of the Whirlwind this divinity also wears ear-pendants and a necklace of turquoise.[372] Of the turquoise in Aztec times we have the testimony of the missionary Bernardino de Sahagun that one variety, presumably that regarded as the finest and most attractive, bore the name _teuxivitl_, which signified “turquoise of the gods.” No one was allowed either to own or wear this as it was exclusively devoted to the service of the gods, whether as a temple offering, or for the decoration of the divine images. Sahagun describes this turquoise as “fine, unspotted and very clear. It was very rare and was brought to Mexico from afar. Some specimens were of rounded shape, like a hazel-nut cut in half; others were broad and flat, and some were pitted as though in a state of decomposition.”[373]