Another member of the corundum family, sapphire is the name given to all color variants except red (ruby). The most well-known hue, however, is a brilliant blue. Because they are transparent and extremely hard (second only to diamond), sapphires can be used in a variety of applications from electronics to scientific instruments.
The deep blue of traditional sapphire comes from trace amounts of titanium and iron. Sapphires can also exhibit asterisms and, more rarely, color changing characteristics. Sapphires commonly come in colors of yellow, pink, purple, green, and white.
Because blue evokes feelings of sympathy and trust, sapphire is a common gemstone for celebrating relationships, and is often used for engagement rings. Sapphire is also the September birthstone.
While found in many parts of the world, the most-valued sapphires traditionally come from Kashmir, Sri Lanka, and Myanmar. Top quality gems are determined by their lack of impurities and quality of color, and deep blues are often the most desirable.