How to Choose a High Quality Sapphire

4 Steps to Finding Your Perfect Sapphire!

So you’re in the market for a sapphire, and you want to do it right. With so many choices out there, and prices ranging from suspiciously low to ridiculously high, you might be thinking, “How am I going to know a good quality sapphire when I see one, and not get ripped off?”

There are 4 main things to look for in a high quality sapphire: 1) Excellent color 2) No glaring inclusions 3) A well proportioned cut 4) The price should reflect the carat size

At first glance, these may seem to be the same as “The 4 C’s” of diamond buying: Carat, Color, Clarity, and Cut, but this article will highlight the major differences between how diamonds and sapphires are graded, and therefore priced. Let’s look at each of these steps, one at a time.

Step #1: COLOR

This C comes in at number one for a reason, with colored stones, Color is King. So, for a blue sapphire, what shade of blue is the most desirable color? The gem industry considers a saturated royal blue, that is, a deep vivid blue with a violet (not green) undertone as “top” color.

What is saturation?
The Swiss Gemmological Laboratory defines it like this: “Saturation is a measure of the intensity or purity of a gem’s hue or color. A gemstone that is free of gray or brown hues is considered to be strongly saturated and is more valuable than a gemstone with lower saturation.” We like to think of it as “juicy” color, it will not seem pastel (white tint) or grayish (black shade).
Keep in mind, just because the industry says this is “top color” doesn’t mean you shouldn’t buy that “ice” blue, or light violet-blue that makes your heart sing. You will actually pay less for lighter colors!
On the other hand, a sapphire that is too dark, like navy blue, is not desirable. Except under the brightest light, the sapphire will look black, dead, with no play of light and color.
It’s important to know that nearly all blue sapphires exhibit some color ‘zoning’ under magnification, it’s a sapphire thing.

What is zoning?
Put simply, it is the appearance of uneven bands of color. Really, this is only a problem if the sapphire appears “striped” from the top view, the way it will be set. If you turn the stone over and see zoning, it isn’t viewed negatively unless you can also see it from the top.

Obvious zoning in a sapphire will detract from its overall appearance

If pink sapphires are your thing, they come in colors from palest pink to ruby red. Once they are actually red enough, they are considered rubies, not pink sapphires. They should also display evenness of color, no matter what that color is.There is no industry standard of ‘ideal’ color for pink sapphires, so it is completely a matter of your personal preference!
Please note, if you are looking at Montana Sapphires, they are judged on their own merits as far as color, since they all have a gray undertone. Unlike the “velvet blue” of Ceylon sapphires, the color of a blue Montana sapphire will be more “denim”, “stone”,“lake”, or “sky” blue. In addition to blue, Montana sapphires also come in many other colors. More detailed information about Montana sapphires can be found here.

Step #2: CLARITY

Another really important difference between diamonds and colored gems is in the way they are graded for clarity. First of all, unlike diamonds, colored gemstones are never graded as “Flawless”.The highest clarity grade a sapphire -or any colored stone for that matter- can have is “Eye Clean” also called “VVS” by some gem labs, which stands for “very, very slight” inclusions, usually undetectable to the naked eye. We will come back to the precise definition of eye-clean in a minute.
Sapphires are considered Type II stones, which are “Usually Included”(see our page on clarity grading).

What are inclusions?
Inclusions are features that were trapped (or included) inside a gemstone while it was being formed in the earth, material believed to be even older than the gem (they were there first after all). These “features” can be other minerals, liquids or gas. Some of these are referred to by self-descriptive names like, “needles”, “clouds”, “fingerprints”, “lily pads”, “centipedes”, “feathers”, and “crystals”.

What is “silk”?
When super-fine needle-like “inclusions” of the mineral rutile intersect each other, you have something called “silk” and under magnification that is what it looks like, a fine weave of fabric. Silk interferes with the regular reflection of light, scattering it within the stone. This prevents a glass-like clarity, but can result in a sapphire that seems to glow!

Are inclusions bad?
All inclusions are like birthmarks that make each natural stone unique. Some types of inclusions provide proof that a sapphire is natural and not synthetic. Other inclusions can indicate whether a sapphire has been heated or not.
However, inclusions that are visible to the naked eye will bring down the value of a sapphire if they detract from its beauty. This would be due to size, structure, an excessive amount of them, or if they are surface-reaching, resembling cracks.

What is “eye clean”?
This does not mean, ‘nothing visible to the eye in any direction when viewed as close as possible’. Within the industry, this is the standard definition of eye-clean: When viewed by a person with normal 20/20 vision, from 10-12 inches away, with the gemstone face-up, under diffused lighting conditions, the gem will not have any visible inclusions. 10-12 inches is about the distance from your eye to the top of a table when seated at it, the way gem dealers view parcels of gemstones. Face up would be the way a sapphire would be mounted in a setting.
Also, don’t mistake a window for clarity, “Look, I can see right through it, it must be really clean.” Windowing is a cut issue, we’re going to talk about that next.
If you are looking for a pink or yellow (or any other color) sapphire and not a blue one, the same guidelines about clarity apply.

Step #3: CUT

Yes, cut really does matter! There is a lot of science behind those little facets. To optimize a sapphire’s appearance, faceting must be done at the proper critical angles, taking into account the refractive index, or light reflection unique to each gemstone. Many sapphires that are cut strictly for weight or diameter, will be lopsided, or worse, exhibit extinction, or an unattractive window.

What is extinction?
First: what it isn’t. Extinction is not when a stone seems darker on one side when turned a certain way, then on the other side if turned the other way. That’s only the difference in light reflection, and it’s typical on ovals, emerald cuts and other elongated shapes. However, if any way you turn it, it seems dark or lifeless, that is extinction, “dead spots” are what we call them, and it is usually a cut issue. If the cutting angles were incorrect, light will not be returned and reflected back to the eye and the stone will look dead, extinct.
Elongated shapes like rectangles, ovals, pears and marquis often exhibit something called a “bow tie” which is a darker or lighter area of reflection in the pavilion. But this effect is not technically extinction. It results from light being reflected back to the eye at different rates because all sides are not equal in length. Sometimes, expert faceters can minimize or even eliminate this optical effect by making angle adjustments during the faceting process. Shapes like rounds, squares or square cushions, and triangles don’t usually exhibit the bow-tie effect.

What is a window?
Can you see right through the stone from table to culet, with facets and color seeming to be only around the edges? That is windowing, mentioned before, it is caused when the pavilion angles (on the bottom side of the stone) are cut shallower than the critical angles required for that particular stone. Instead of light being bounced around and reflected back to the eye, it just goes right through it and keeps on going.
See this picture for an example of an enormous window:

A poor cut will result in an unattractive window

A small window can appear to “close” when it is set, minimizing in appearance in the mounting because there is no back lighting. When you have an otherwise good looking sapphire but it has a small window, it may have been left that way to keep it at the next desirable carat weight. For example, instead of weighing “1.95 carats”, leaving a small window might bump it up to “2 carats”.
Sapphires can be found in all different shapes but are most commonly cut into rounds, ovals, or cushions because these maximize the natural shape of the rough material. A well-shaped piece of rough in the hands of a skillful cutter will only yield a cut stone about 1/3 of its original weight if cut for beauty and not just for size.
The “brilliant cut” which was designed for diamonds, can work well on lighter sapphires, but doesn’t usually look that good on medium to deep color sapphires. Sapphire has a different refractive index than diamond and needs to be faceted to show the color off best, as well as to maximize light reflection.
Other cut issues that you should not see in a top quality sapphire are chips, poor polish, and wonky facets.
It is important that the sapphire you choose was cut for beauty, not simply for weight or diameter.

See the difference between these two sapphires?

A native cut will be done for maximum size and/or weight

A properly cut stone will maximize the appearance of the stone’s color and brilliance, with size and weight being a secondary consideration

Step #4: CARAT

Weight is the last and possibly least important of the four C’s, in some ways. When it comes to sapphires, and all colored gems, the important measurement will be the “face up” size or diameter, which is measured in millimeters, not carat weight.
A 1 carat round brilliant cut diamond will be around 6.5mm because diamonds are cut at the same angle, with the same depth, most of the time.
As you just read under “Cut”, every gemstone has a different refractive index, which affects how light is reflected. Gemstones also have different specific gravity, or weight. A sapphire is denser than a diamond. It’s like the elementary school riddle, “What weighs more, a ton of feathers or a ton of bricks?” A ton weighs a ton, but the denser item will take up less space. So while a 1 carat round brilliant diamond will be 6.5 millimeters, a round brilliant “Roulette” style cut sapphire that is also 6.5mm may weigh from 1.2 – 1.5 carats, but will fit in that same 1-carat-diamond setting. Or looking at it another way, a 1 carat round sapphire may measure anywhere from 5.7 to 6 mm.
All this is not to say that carat size is totally irrelevant! Colored stones are still priced per carat, and the bigger the sapphire the rarer it is, the higher the per-carat price will be. Just as an example, if a 1 carat sapphire is $1500, you might think a 3 carat should only be three times that, $4500, right? Well…not really. A 3 carat sapphire that is just as well cut, clean, and has comparable color to the 1 carat stone will be so much rarer that it will likely be closer to $2500 per carat, that is, $7500 for the stone.

Remember these 4 steps when looking for a good sapphire: choose “juicy”, even color; no glaring inclusions or visible “junk”; a well-proportioned cut appropriate for sapphire; and lastly carat size, which will be determined by your budget.

For a large selection of well cut, high quality blue sapphires available for purchase, please see our Blue Sapphires. For pink, purple, yellow, orange, or green sapphires, please visit our Sapphires page to choose by color. If you are interested in buying a Montana sapphire, please see our selection of Montana Sapphires.

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