There was in the South Kensington Museum, in London, a splendid sapphire of a peculiar tint. In the daylight it shows a beautiful rich blue color, while by artificial light it has a violet hue and resembles an amethyst. In the eighteenth century this stone was in the collection of Count de Walicki, a Polish nobleman, and Mme. de Genlis used it as the theme of one of her stories, entitled “Le Saphire Merveilleux.” Here the sapphire is used as a test of female virtue, the change of color indicating unfaithfulness on the part of the wearer. If the owner of the stone wished to prove that the subject of the test was innocent, she was made to wear the sapphire for three hours of daylight; but in the opposite case the test was so timed that it began in daylight and ended when the candles or lamps had been lighted. This sapphire, still known as the “Saphire Merveilleux,” was for a time in the collection of the Duke of Orleans, who bore the name of Philippe Egalité during the French Revolution. The star sapphire is that variety of sapphire in which, when the stone is cut and rounded off horizontal with the dome of the crystal, the light is condensed across the three lines of crystalline interference. Three cross lines produce a star which moves as a source of light, or as it is moved from the source of light. Star sapphires very rarely possess the deep blue color of the fine blue sapphire; generally the color is somewhat impure, or of a milky-blue, or else a blue-gray, or sometimes almost a pure white. The blue-gray, gray, and white stones frequently show a much more distinct star, possibly from the fact that there are more inclusions between the layers of the crystals than with the darker blue stones, as it is the set of interference bands that produces the peculiar light. Just as the eye agate was used in some countries to preserve against the Evil Eye, so the moving star is believed by the Cingalese to serve as a protection and a guard against witchcraft of all kinds. The great Oriental traveller, Sir Richard Francis Burton, had a large star sapphire or asteria, as it was called. He referred to it as his talisman, for it always brought him good horses and prompt attention wherever he went; in fact, it was only in those places where he received proper attention that he would show it to the natives, a favor they greatly appreciated, because the sight of the stone was believed to bring good luck. The fame of Burton’s asteria travelled ahead of him, and it served him well as a guiding-star. De Boot, writing in the seventeenth century, states that such a stone was called Siegstein (victory-stone) among the Germans. [Illustration: Rubellite from the Shan Mountains, China. Used as an idol’s eye in India Star of India—Star Sapphire Engraved Emerald—East Indian Carving—17th Century GEMS FROM THE MORGAN-TIFFANY COLLECTION.]