Tropical Gemstones. Carol Higgins Clark

      Asian origins: India, Myanmar, Sri Lanka, Thailand, Cambodia, Vietnam

      The sapphire is the serene, more subtly beautiful sister stone of the ruby. Both gems belong to the corundum mineral family and are essentially crystallized aluminum oxide. Red corundum—which consists of aluminum oxide and traces of chromium—is called ruby, while blue corundum—colored by traces of titanium and iron—is known as sapphire. Like rubies, sapphires are second in hardness only to diamonds.

      Corundum containing other trace elements appears in a spectrum of colors, including yellow, violet, pink, green and orange. Any corundum gemstones which are not red or blue are called "fancy sapphire."

      Blue is by far the most popular of the sapphire colors. The name derives from the Greek sapphirus, for blue. Since early times, the sapphire has been associated with celestial forces. In ancient Sanskrit it is referred to as sauriratna, "sacred to Saturn." Buddhists consider the sapphire a symbol for peace and faithfulness in love, making it a popular choice for an engagement ring gem.