The sapphire, birthstone for September, is a relative of July’s birthstone, ruby. Like ruby, it is a form of the mineral corundum, a normally drab grey mineral. Red corundum is called the ruby, while all other gem quality forms of corundum are called sapphires.
Typically, sapphires appear as blue stones, ranging from very pale blue to deep indigo, due to the presence of small amounts of titanium and iron within the crystal structure.
The most valued shade of blue is the medium-deep cornflower blue. Sapphires also occur in other natural colors and tints – colorless, gray, yellow, pale pink, orange, green, violet and brown – called fancy sapphires.
These different colors are caused by different kinds of impurities within the crystal. For example, yellow sapphires get their color from ferric iron, and colorless gems have no contaminants.
The biggest source of sapphires world-wide is Australia, especially New South Wales and Queensland. Found in alluvial deposits of weathered basalt, Australian sapphires typically are blue stones with a dark and inky appearance.
Kashmir, in India, used to be a well-known source of the cornflower-blue stones. In the United States, a major source is the Yogo Gulch Mine in Montana that mostly yields small stones for industrial use.
The word sapphire has its roots in several ancient languages: the Arabic safir, the Latin sapphirus (meaning blue), and the Greek word sappheiros for the island of Sappherine in the Arabian Sea where sapphires were found in ancient Grecian times.
Ancient Persians called sapphire the “Celestial Stone.” It was the gem of Apollo, Greek God of prophesy and was worn by worshipers visiting his shrine in Delphi to seek his help. It was used by ancient Etruscans as far back as the 7th century B.C.
September’s birthstone, the sapphire, has been popular since the Middle Ages. The celestial blue color of this gemstone symbolized heaven and attracted divine favor and wise judgment.
Greeks wore sapphire for guidance when seeking answers from the oracle. Buddhists believed it brought spiritual enlightenment, and Hindus used it during worship. Early Christian kings cherished sapphire’s powers of protection by using it in ecclesiastical rings.
Ancient Hebrews believed that the Ten Commandments were engraved on tablets of sapphire, though historians now believe the blue gemstone referenced in the Bible may have been lapis lazuli.
Classical violet-blue sapphires traditionally came from the Kashmir region of India between the late 19th and early 20th centuries. The world record price-per-carat for sapphire was set by a gemstone from Kashmir, which sold at auction for $242,000 per carat (more than $6.74 million total) in October 2015.
Famous star sapphires, like the 1404.49-carat Star of Adam, the 563.4-carat Star of India and the 182-carat Star of Bombay, came from Sri Lankan mines.
Australia was a significant source of sapphires until deposits were discovered in Madagascar during the 1990s. Madagascar now leads the world in sapphire production.
In 1902, French chemist Auguste Verneuil developed a process to make synthetic sapphire. The abundance of synthetic sapphire unlocked industrial applications spanning integrated circuits, satellite communication systems, high-durability windows, and scientific instruments.
Sapphire became a symbol of royal love in 1981 when Britain’s Prince Charles gave Lady Diana a 12-carat blue sapphire engagement ring. Prince William later gave this ring to Catherine Middleton when he proposed in 2010. Today, top-quality blue sapphire remains one of Mother Nature's rare gemstones.
Sapphires make stunning gifts for anyone born in September or celebrating a 5th or 45th wedding anniversary. Whatever your reason for buying sapphire, you can’t go wrong with this brilliant gemstone, whether you’re seeking classical blue or another shade of the sapphire rainbow.
Like diamonds, sapphires are assessed by the 4Cs; color, clarity, cut, and carat size, in addition to country of origin.
Color is the key indicator of a sapphire’s price. The highest valued sapphires are vivid blue, sometimes with a violet hue. Secondary hues of green or gray detract from sapphire’s value.
Sapphire gemstones come in almost any color except red, which is classified as ruby. Pinkish orange varieties are known as padparadscha, and these typically have higher per-carat values than other colors of fancy sapphire.
Some sapphires even exhibit color change, shifting from blue in daylight or fluorescent light to reddish purple under incandescent light, much like the color-changing alexandrite.
Blue sapphires typically have better clarity than rubies, though they often have long, thin rutile inclusions called “silk.” Inclusions generally make gemstones less valuable, but they can increase the value of sapphires that exhibit asterism.
Blue sapphires can range in size from a few points to hundreds of carats. Most commercial-quality blue sapphires weigh less than five carats. Large blue sapphires, while rare, are more readily available than large rubies.
The 423-carat Logan Sapphire in the National Museum of Natural History is one of the largest faceted gem-quality blue sapphires ever found. The Star of Adam is the largest blue star sapphire, weighing 1404.49 carats.
Sapphires are often treated with heat to improve color and clarity. Untreated natural gemstones are somewhat rare and incredibly valuable.