Sapphire is one of the four precious gems (diamond, emerald and ruby are the other three). It is the birthstone for September and for the Zodiac signs Pisces, Taurus, Virgo and Sagittarius.
Sapphire is a variety of the mineral corundum. Trace amounts of other elements such as iron, titanium, chromium, copper or magnesium color the corundum blue, yellow, purple, orange, green or pink. When chromium impurities in corundum yield a red stone, it is called ruby. Pure corundum has no traces of other elements and is called white sapphire. When the trace elements produce an orangey pink corundum, it is called padparadscha which means lotus flower in Sinhalese, the language spoken in Sri Lanka where stones of this color were originally found.
Star sapphires contain intersecting needle-like inclusions that cause the appearance of a six-rayed star. The inclusion is often the mineral rutile. Star sapphires can be any color from shades of blue to pink, orange, yellow, green, lavender, gray or black. The most desirable color is a vivid intense blue.
Color-change sapphire is a rare variety which exhibits different colors in different types of light. The stones are blue in outdoor light and purple under incandescent indoor light.
Tradition holds that Moses was given the Ten Commandments on tablets of sapphire, making it a sacred gemstone. Ancient Persians believed sapphire gave heaven its blue color. In ancient Greece and Rome, kings and queens were convinced sapphires protected them from envy and harm. Because sapphires represent divine favor, they were the gemstone of choice for kings and high priests. Ordinary people thought sapphires attracted heavenly blessings.
Sapphires symbolize truth, compatibility, commitment and mutual understanding which make them the perfect gem for engagement rings. They are also said to contribute to mental clarity and perception. Sapphires are also believed to promote financial rewards.
More about sapphires and other gemstones can be found in Jewelry Facets.