Sapphires

Sapphires have been the darling gemstone of the royalty and well-to-do for centuries, so it’s no surprise that they’ve gained in popularity of late as the center stone or accent stone in bridal and fashion jewelry. That Prince William proposed to Kate Middleton with his mother’s 18 carat blue sapphire engagement ring certainly set quite the precedent, and has sparked a growing trend amongst couples searching for colored gemstone engagement rings.

But before Princess Di received her gorgeous blue beauty, these indigo rocks had been cherished for generations as symbols of good fortune, virtue, holiness, and wisdom. The ancient Persians believed that the earth rested on a giant sapphire, which reflected its color to the sky. Another legend holds that the tablets of the Ten Commandments were made of sapphire and were so strong that they could withstand a hammer’s swing but would smash the hammer to pieces if struck.

The word sapphire most likely comes from the Hebrew “sapir,” as it is understood in the Hebrew Bible to refer to blue sapphires. Sapphires, members of the corundum family of minerals, usually refer to the blue variety unless otherwise stated. The other varieties include pink, yellow, green, orange, brown, clear and red — otherwise known as rubies. Sapphire is September’s birthstone and the traditional wedding anniversary gift for the 5th and 45th year. They score a 9 on a scale of 1 to 10 on the Mohs’ scale of mineral hardness, second only to diamonds at a perfect 10.

Let’s take a look at the 4 C’s of sapphires in their order of importance.

Color

Beautiful 5.09ct Sapphire with Great Saturation

Beautiful 5.09ct Sapphire with Great Saturation

Color is the most important factor when purchasing a colored gemstone. The color of the sapphire is what captivates us, and draws us in for a closer look. But this is only when the color of the stone has the proper measures of hue, tone, and saturation. Without these, the stone may appear dull, colorless, and gray.

A sapphire’s hue describes the stone’s balance of color as it relates to its neighbors on the color wheel. With blue sapphires, for example, we would call the stone’s color either blue, slight green, strong green, slight purple, or strong purple. The closer you can get to “true” blue, the more expensive and desirable the sapphire will be. It’s common to refer to this variety of sapphires as “cornflower blue,” as the cornflower is one of the few flowers said to be purely blue and not violet or purple like most other “blue” flowers. Yogo sapphires, mined in Yogo Gulch, Montana, are said to be of this cornflower blue variety, and are famous for their lack of inclusions (high clarity).

Tone describes how light or dark the color is with the range going from very light to very dark. It’s best to stay in the medium to dark range with tone, as the lighter the tone, the more watered down the overall look of the sapphire.

And finally the saturation describes how vibrant the color is with the range going from dull/weak to pure vivid. The closer to pure vivid you can get, the better the sapphire’s color will appear to you, and the more money it will fetch.

As we said, the most desirable sapphires will have vivid, highly saturated color without areas of brown or gray. These areas are known as extinction and are affected by lighting quality, position, tone, and cut. Usually the darker the stone’s color, the darker the extinction will be as well.

0.96ct Sapphire with Weak Saturation

0.96ct Sapphire with Weak Saturation

Whereas diamonds have an elaborate, standardized color-grading system, sapphires and other colored gemstones have no such similar way to asses color across the board. This lack of uniformity means that it’s harder to compare two sapphires since one won’t be graded “D” and other “J.” Rather, you will have use your own judgment about which colors appear vibrant and alive to you. Of course, the better the sapphire’s color, the higher the price tag will usually be, but be sure to buy only from reputable gemstone vendors.

Besides the renowned blue sapphire, there is the Padparadscha Sapphire, an extremely rare and sought-after pink-orange fancy sapphire originally found in Sri Lanka. This sapphire can fetch over $20,000 per carat! The name comes from Sanskrit/Sihalese “padma raga,” which means “lotus color” since the stone’s color is reminiscent of a lotus flower.

After the blue and Padparadscha, the fancy pink sapphire ranks third in popularity for its prized hot pink hue. These striking pink marvels are generally found in Burma or Sri Lanka. As the amount of chromium increases in the corundum, the shade of pink deepens as well. It is important to note that there is often a fine line between what is called a pink sapphire and a red ruby. In the United States, there must be a minimum color saturation in order for the stone to be called a ruby. In other places, the term ruby may be used more loosely.

Clarity

It is highly unlikely to find sapphires without any inclusions, or imperfections, at all. If there are no inclusions, gemologists will suspect the sapphire to be fake or treated. As we explained in our article about rubies, all sapphires will have rutile needles or “silk”. Most sapphires on the market today have been heat-treated to improve their clarity and color. (If they’ve not been treated at all, they can be sold for big money.)

Whereas with diamonds, gemologists use 10x magnification to inspect the diamond’s inclusions, with colored gemstones, we are only concerned with non-magnified careful examination. In other words, we are looking to see if the stone is “eye-clean” to the naked eye. The cleaner the stone, the higher the price tag.

While the appearance of inclusions are not usually regarded as positive, in the case of asterism, the opposite is true. When light is reflected off the silk, a star effect is created, making the sapphire appear to have a three or six-point star on the face of the stone. Asterism is rare and also increases the value of the stone. The Black Star of Queensland is said to be the largest mined star sapphire in the world, weighing in at 733 carats.

Cut

There are no standardized cuts for sapphires as there are with diamonds. Whereas with diamonds you could choose an “ideal” cut to showcase the diamond’s color and fire, with sapphires — and most colored gemstones — you are relying on the gem cutter to maximize each individual sapphire’s unique combination of color, clarity, and brilliance.

In general, a well-cut sapphire will be symmetrical and reflect light at the proper angles in order to enhance the stone’s luster. It is often the case that gem cutters will cut more deeply when the sapphire’s tone is light. This makes the stone appear to have a deeper, darker color. And the opposite is also true: if the sapphire is very dark, then the gem cutter may choose to make a shallow cut to bring more light in and thereby lighten the overall look of the stone.

The most common shapes of sapphires are usually oval, round, cushion, and emerald. The cabochon cut is also prevalent as a non-faceted, polished alternative. This shape displays the sapphire as a smooth oval, convex dome, and is the best way to show off a star sapphire’s asterism.

Carat

Just as gemstones vary widely across the spectrum in terms of their color and hardness, so too they also differ in density. This is apparent when we consider the carats, or weight of the sapphire vis a vis the carat weight of a diamond. Since sapphires are usually heavier, a one carat sapphire will look smaller than a one carat diamond. It is more accurate to measure the size of the sapphire in terms of its millimeter diameter. A rule of thumb is that a one carat sapphire generally measures 6 mm.

Ready to Buy?

When you’re ready to buy a sapphire, it’s essential to see a high quality image of the stone for yourself. As you now know, color is the most important factor when buying a sapphire, and it would really be a foolish gamble to make a purchase without investigating the actual stone’s hue, tone, and saturation. James Allen is the only vendor online that offers both great prices and full 360 degree high quality photos, and because of this, we steer our readers to JA when they are in the market for precious gemstones.