The fabled sapphire, one of the four gems called precious today, is an extremely hard variety of corundum occurring in transparent or translucent crystals. Corundum is aluminum oxide, and the rich blue color of sapphire is believed to be caused by the presence of titanium and iron oxides. The finest sapphires come from Burma, Thailand, India and other parts of the east. According to ancient oriental legend, the earth rested on a giant sapphire, whose blue color was reflected in the bowl of the sky. Though the stone was known in the west, it was rarely used by any but royalty until the Christian era. This rarity contributed to its reputation as a magic stone of immense and all encompassing power, capable of warding off every kind of pestilence and contagious disease. The sapphire is also reputed to bring good luck to its owner and to promote wisdom and clarity of mind. The deep and vibrant blue of this gem makes its precious reputation a deserved one.