Sapphire

Though associated with blue, the sapphire family includes every important color except red. Predominantly red sapphires are called ruby. (The word sapphire comes from the Latin sapphirus, which has been traced back to the Sanskrit sanipriya, which means “dear to the planet Saturn.” Some say sapphirus originally referred to lapis and later to other opaque blue gems.)

Sapphires are found in some of the most exotic places in the world, including Sri Lanka, Burma, Kashmir, Madagascar, Tanzania, Kenya, Thailand, and Australia. Sri Lanka (formerly Ceylon) produces exceptional blues and yellows, traditionally light to medium in saturation, as well as other colors, including pink, green, and purple.

Ceylon sapphire has been an important stone throughout history, and great quantities are still mined every year. Ceylon sapphires with a milky, whitish-yellow body color, called “geuda,” have been heat-treated to create beautiful blue gems for decades. Recent finds in Madagascar are producing blues and pinks that rival the Ceylon stones. Stones from Burma are known for their rich, dark-blue colors, while Tanzania and Kenya are producing color-change sapphires and other multicolored corundums. The most highly prized sapphires of all are the cornflower blues from the highlands of Kashmir.

History and romance. When Prince Charles gave Diana Spencer a Ceylon blue sapphire engagement ring, the stone was catapulted back into the limelight. The prince’s gift, though untraditional, was entirely appropriate—another name for the color of sapphire is royal blue.

Color variations. Like all colored gems, sapphire’s most important characteristic is color—the more saturated and pure the hue, the more highly prized the stone. Some of the world’s finest sapphire is found right here in the United States. Mines in Montana, specifically those in Yogo Gulch, produce near-equivalents of Kashmir’s cornflower blues. Other Montana mines provide large quantities of material that can be heat-treated to yield gemstones in a variety of colors.

Qualities. The color of sapphires from Kashmir is often likened to the color of the cornflower and is generally described as a milky, velvety, saturated blue. Among blue sapphires, it’s the most prized color, but Burma’s rich, dark, saturated blue gems are considered a close second. Sri Lankan padparadscha (“lotus blossom”) sapphires are saturated pink-orange gems, medium to medium-light in tone. Among sapphires, the padparadschas are the most coveted by collectors. The values of change-of-color sapphires from various localities are based on strength of color and degree of color change. Clarity is important only insofar as common blue and colorless zones are not apparent face-up. Many Sri Lankan stones are cut with large color zones apparent only when viewed parallel to the girdle plane of the gem. This method of cutting retains weight from the rough yet yields a beautiful gem face-up. Remember that a color-zoned gem will be worth less than one that has even color distribution throughout.

Value. The value of sapphire depends mainly on color but can be affected by origin. Kashmir and Yogo sapphires can double or triple in value based on their saturated “cornflower” blue color. The label “Kashmir,” however, doesn’t guarantee that a sapphire is from Kashmir or that it has a cornflower blue hue. Since it’s the color of a Kashmir sapphire that creates value, don’t base your purchase of such a stone solely on origin.

Meanwhile, the abundance of Madagascar material is keeping prices of good-quality sapphire from nearly all sources very affordable.

The name “padparadscha” can increase the value of a gem only if the color is a fair combination of pink and orange. Some of the African padparadscha appears to be only slightly pinkish orange, and many believe it should be classified as simply an orange sapphire. Again, use caution in accepting labels.

Pricing. According to The Guide, Fall/Winter 1999-2000, the finest-quality sapphires of 1 ct. to 2 cts. cost $2,500 to $3,350 per carat. Top-grade Burmese sapphires of the same size range in price from $2,500 to $3,500 per carat. Kashmir sapphires, extra-fine Yogos, and padparadschas command even higher prices. Pink sapphires are currently priced at $800 to $1,600 per carat.

Enhancement disclosure. Most sapphire (99.99%, by some estimates) is heated to improve color. Because the enhanced color is quite stable, heat treatment is an accepted practice. Yellow sapphires, however, are sometimes irradiated, and the resultant color may not be stable. Placing the gem under intense light is a sure way to uncover irradiated color, but unless you plan to re-irradiate the stone, the color will be permanently lost.

It takes less heat to treat sapphire than it does to treat ruby, and pink sapphire from Madagascar requires even less heat than other sapphire. Telltale signs of heat treatment, such as exploded crystals with accompanying strain halos, generally aren’t seen in heated Madagascar pinks.

Ninety-nine percent of Kashmir and Yogo Gulch sapphires are natural color. Because there’s a dramatic price difference between untreated and treated sapphire, we recommend disclosure of all enhancements.

Care and cleaning. With a hardness rating of 9 on the Mohs scale, all corundum is difficult to scratch. Neither moderate heat nor ultrasonic cleaning causes problems for sapphire, but the gem’s value dictates caution when cleaning or repairing sapphire-set jewelry.

Bench settings and precautions. While the bench jeweler should always be aware of the unusual, sapphires in general can withstand most repair and cleaning methods. Phenomenal sapphires, however, especially “black” star sapphires, should be handled with care—moderate pressure can cause them to split.

What is true of many other gems is also true of colored sapphires: There may be less there than meets the eye. A colorless sapphire can be enhanced through diffusion of color into the top layer of the gem. Diffusion-treated sapphires can lose their color if they’re chipped or repolished. Always examine all colored sapphires before you work on them to ensure that you don’t have a diffusion-treated stone.

Recommended reading. For more information, see Ruby & Sapphire by Richard W. Hughes (RWH Publishers, 1997