The turquoise has long proved a puzzle to the most experienced dealers in gems, on account of its singular property of changing color without apparent cause. Ordinarily it is of a beautiful blue--about the color of a robin’s egg. This color sometimes changes to green, and again, though unfrequently, to white. In relating his experience with this stone to me, an old friend described his surprise as well as alarm at having a very valuable specimen, which was “beautifully blue” when put in the workman’s hands to be set with diamonds, returned to him covered with a white film, nearly concealing the original blue color. As the turquoise itself was worth several hundred dollars, it really was a rather serious matter. The erratic stone, however, was put away in the safe. When the purchaser called for it on the following day, on its being taken out of the box, it was found that the true color had partly returned, one half of the stone being blue, and the other half white. “And we even fancied” continued my informant, “that we could see the color change as we watched it.” This change of color in the turquoise gave rise to the belief that its hue varied with the health of the wearer, it being blue when the wearer was in good health and green or white in the case of ill-health, or as put into verse:-- “A compassionate turquoise that doth tell By looking pale the wearer is not well.” As coral is again becoming quite fashionable, we recall that it was once considered a sure protection against the Evil Eye, and is so still in Italy, where the little coral charm shaped like the hand, with the thumb and middle finger closed (a charm against witchcraft), comes from. It is also a more or less general belief that coral or red beads, worn round the neck, prevent nose-bleeding, on the principle, we suppose, that like cures like. The carnelian, shaped in the form of a heart, was formerly much worn as an amulet. The amethyst, as its Greek name implies, is considered an antidote to intoxication. It has now a formidable rival in the gold-cure. There is an anecdote of the first Napoleon which affirms that he took a valuable amethyst from the crown in the coffin of Charlemagne. The stolen stone later came into the possession of Napoleon III., who wore it as a seal on his watch-guard. In his will he bequeathed the stone to his son as a talisman. On making her escape from Paris, in 1870, the empress took the historical stone with her. The carbuncle was formerly believed to guard the wearer against the danger of breathing infectious air. It was also said to have the property of shining in the dark, like a burning coal, thus investing it, in the minds of the credulous, with supernatural power. This, be it said, was an Old-World superstition, which is referred to in some verses written by John Chalkhill (1649), describing a witch’s cave:--