Something Blue: Choosing Sapphire Engagement Ring Stones


Summary
Sapphires are both traditional and trendy gem choices for engagement rings. They can cover “something old” or “something new” but will really wow when brides need “something blue.” Sapphires are rare, beautiful, durable … and expensive. When you’re shopping for sapphire engagement ring stones, some knowledge of this gem’s optical and physical properties, grading, and varieties might save you some time and money.
Reading time: 16 min 2 sec
triangle-cut sapphire - sapphire engagement ring stone
Medium-dark blue 2.10-ct sapphire, 7.6 x 9.2 mm, triangle cut, Sri Lanka. © The Gem Trader. Used with permission.

Are All Sapphires Blue?

Sapphires come in a great variety of blue colors, from the brilliant sky blue of a cloudless day to the royal blue of twilight to the inky navy of night. Any blue sapphire engagement ring is sure to become an enduring classic. However, sapphires also come in every color imaginable, except red.

The term sapphire encompasses all non-red gem-quality corundum. (Red gem-quality corundum is considered ruby). Completely colorless, pure corundum consists of aluminum and oxygen and can’t form if silicon is present. Silicon ranks as one of the most abundant elements in the Earth’s crust, so this makes corundum relatively rare. Trace elements give corundum gems their color. Chromium makes rubies red. Iron and titanium create blue sapphires. Variable levels of these and other elements create other colors, including green, yellow, orange, and pink. These non-blue sapphires are sometimes called “fancy sapphires.”

Blue is the most highly valued color of sapphire and has the strongest popular association with this gemstone. When shopping for sapphires, if you encounter the term “sapphire” without any color description, it most likely refers to blue sapphire. In fact, blue sapphires set the color standard for blue gems of any kind. For example, the most valuable tanzanites are often described as “sapphire-like” in hue.

If you want a sapphire engagement ring but would prefer another color besides blue (or a significant drop in price), consider a fancy sapphire stone. Of these, pink and pink-orange padparadscha sapphires rank as the most expensive.

fancy sapphires, ovals - sapphire engagement ring stones
Fancy sapphires in a variety of colors. Faceted ovals, 7 x 5 mm. © Navneet Gems & Minerals. Used with permission.

The Romance of the Sapphire Engagement Ring: Then and Now

Sapphires have many symbolic associations and have long been popular as engagement ring stones among nobility and celebrities. While still a poor soldier, Napoleon splurged on a ring set for Josephine with an inverted pear-cut sapphire and an upright pear-cut diamond, each stone just one carat in size. This ring style, known as “You and Me,” was incredibly popular during the 18th century. 

Princess Kate’s engagement ring consists of an oval 12-ct Ceylon sapphire surrounded by a halo of diamonds. In the 1980s, Prince Charles had picked the center stone with Lady Diana and had it set in a ring. Prince William, their son, presented the ring to Kate Middleton in 2010. It has since become one of the most famous engagement rings in the world.

Princess Kate inspired ring - sapphire engagement ring stones
Inspired by Princess Kate’s engagement ring, this ring consists of a lab-created 7 x 5 mm oval sapphire with a sunburst halo of diamonds on white gold. © CustomMade. Used with permission.

Other celebrities with notable sapphire engagement rings include Penelope Cruz and Elizabeth Hurley.

What Difference Does a Sapphire’s Source Make?

Although sapphires are found all over the world, their origins have a great impact on prices. The most important locales include Kashmir, Myanmar (formerly Burma), Sri Lanka (formerly Ceylon), Thailand, Cambodia, Australia, Madagascar, and Montana.

These sources are so well-known for producing quality sapphires that any sapphires from these regions automatically hold a certain prestige. However, not all of the sapphires from these regions demonstrate the characteristics of the top stones. Furthermore, just because a trader refers to a sapphire with a regional name doesn’t mean it actually comes from that region. For example, a “Ceylon sapphire” may simply indicate the stone shows attributes typical of sapphires from Sri Lanka. Always ask gem dealers what they mean when they use such regional descriptors for sapphires. Sapphires from Kashmir, Myanmar, and Sri Lanka could cost more than stones of equal quality from other sources simply because of the prestige attached to these locales.

Our sapphire buying guide describes the qualities associated with the most well-known sapphire sources.

If all you want is a beautiful sapphire, ignore the regional descriptors and evaluate the stone on its own terms.

American consumers who want local, ethically sourced, untreated sapphires should consider stones from Yogo Gulch, Montana. These show beautiful “cornflower” blue color even without heat treatment. For those who want to involve themselves in the engagement ring creation process from beginning to end, some Montana mines allow tourists to scavenge for stones nearby for a daily fee.

Yogo Gulch, Montana sapphire - sapphire engagement ring stone
0.65-ct Yogo Gulch sapphire. Image taken at Barnes Jewelry, Helena, MT with permission of owners. Photo by Montanabw. Licensed under CC By-SA 3.0.

How to Pick a Sapphire Engagement Ring Stone

Sapphire prices vary dramatically depending on the stone’s quality. Our sapphire buying guide thoroughly covers the Four Cs of gemstone grading — color, clarity, cut, and carat. Here are some basic guidelines for evaluating sapphires as well as some particular characteristics to watch for when having your stone cut and set in a ring.

Color

Color is the single most important attribute of a sapphire. Classic blues should have a pure to violetish blue hue. Though acceptable, traces of green will diminish the value of a blue stone. Ideally, the stone should have strong to vivid saturation with medium to medium-dark tone. The saturation should be as intense as possible without compromising brilliance (light return) or darkening the tone. 

Pleochroism

Stones that exhibit pleochroism show two different colors depending on the viewing angle. All sapphires have pleochroism. Gem cutters usually orient blue sapphires so you can see their violetish-blue color when viewing the table, the large facet on “top” of the gem. This makes it so you can only see the greenish blue color from the side. The stronger the pleochroism, the lower the price. Strong green pleochroism is especially undesirable for blue gems.

Color Zoning

Sapphires often exhibit color zoning. Thus, some stones might show bands of dark and light blue. In dramatic cases, the bands may even alternate between blue and colorless material. These bands of color are growth marks. If the gem contains enough of the original crystal, you can see that the bands form a hexagonal pattern. This echoes the hexagonal “spindle” shape of the original crystal.

While many gemologists and gem collectors find these bands fascinating, some sapphire engagement ring stone shoppers may not. Ring stones generally should have a color as even as possible. If obvious, color zoning will drop the stone’s price significantly. For adventurous types, this could represent a bargain.

color zoned sapphire - sapphire engagement ring stones
This medium-dark green sapphire shows yellow color zoning. 0.98-ct, 6 x 4.1 mm, rectangular step cut, Kenya. © The Gem Trader. Used with permission.
Windowing

Even the best color won’t show well if the stone contains a window — a see-through spot at the bottom of the pavilion. The cut of a gem can create this effect. If a stone is too shallow or its angles not proportioned correctly, light will leak out of the pavilion instead of bouncing off the pavilion facets and returning to the viewer through the table.

Gem cutters sometimes deliberately use windowing to lighten the color of a dark sapphire.

To check for windowing, hold the stone against a piece of printed paper. If you can see print through it, then that stone has windowing. If you don’t have printed paper handy, just wave your finger back and forth behind the stone. With the best sapphires, you shouldn’t see your finger at all.

Logan Sapphire - sapphire engagement ring stones
The Logan Sapphire from Sri Lanka, the second largest (blue) sapphire ever found, weighing 422.99 cts (84.6 g). Although stunning, this stone demonstrates windowing. Look at its enormous patch of lighter color. From the collection of the Smithsonian Museum of Natural History. Photo by Chip Clark, Smithsonian staff. Public Domain.
Extinction

All stones will show a certain amount of extinction, dark patches without light return. However, no more than 25% of the stone should show extinction. Extreme extinction occurs more commonly in dark stones or those with deep pavilions.

Sometimes, gem cutters will create extinction in order to saturate the color of a light stone.

To check for extinction, hold the stone up against a sheet of white paper. Now, see how much of the stone’s true color reflects back to you versus how much of the stone appears black.

The more brilliance and less extinction and windowing a sapphire exhibits, the more beautiful it will appear.

extinction - sapphire engagement ring stones
The black patches on this relatively light-colored sapphire are extinction. Photo by Thomas Samson. Public Domain.

Clarity

Sapphires will most often have eye-visible inclusions. These are fractures, minute crystals, and even liquids and gasses trapped inside the stone that you can see unaided.

Typically, such inclusions won’t impact the sapphire’s value unless they obviously detract from its overall beauty. In some rare cases, inclusions can create valuable star sapphires, which show asterism or a “star stone” effect. Inclusions also create the prized “velvety” look of Kashmir sapphires. However, rich and dark colors in sapphires will usually mask the majority of these inclusions.

Sapphires rarely receive the highest clarity grade for a colored gem, eye clean. You should expect to pay a premium for them. You’ll more likely come across slightly or moderately included sapphires. Slightly included sapphires are considered high-quality sapphires. These will have inclusions somewhat easy to see with the naked eye. On the other hand, moderately included sapphires will have inclusions fairly obvious to the naked eye.

Although clarity isn’t usually the foremost consideration when shopping for colored gemstones, you should still avoid stones with obvious inclusions that detract from the stone’s beauty or that affect its durability. (A gemologist can better assess if inclusions, especially “feather” and “veil” fractures, affect a gem’s structural integrity).

To check a sapphire’s clarity, simply rock the stone back and forth under a light. See if any inclusions jump out at you. If you find none of them distracting, that stone likely has good clarity.

Cut

For colored gemstones like sapphires, cut standards are fairly forgiving. The average consumer can evaluate them easily.

Some sapphires, particularly star sapphires and stones with beautiful color but low clarity, receive cabochon cuts. However, for engagement rings, the vast majority receive faceted cuts.

teal sapphire - sapphire engagement ring stones
The ring contains a 0.93-ct sapphire, most likely from Montana, set in 14k white gold and accented with moissanites on the shank. © CustomMade. Used with permission.
Symmetry

The most noticeable aspect of a faceted stone is symmetry.

A round stone should have perfectly round outlines, without noticeable flat spots or bulges.

Oval, square, or rectangular stones have two lines of symmetry. Make sure that the stone is balanced across the length and width. If the stone is folded top to bottom and side to side, each side should match up perfectly with the other.

Pear and heart-shaped stones have only one line of symmetry. Thus, the two sides should appear exactly the same. If the shape is folded in half, the two sides should match up.

It’s also important to examine the stone from the side. Make sure the pavilion angles are symmetrical and that the stone is neither too deep nor too shallow.

Shape Appeal

Next, consider the faceted sapphire’s shape appeal.

For oval, pear, and heart stones, the heads or lobes — the wide, rounded parts — should be full, not flat.

Pears, hearts, and marquise shapes should have sharp, well-defined points.

The gem’s shoulders — the slope descending from the head or lobes — should be smooth and even. Too high shoulders will make the point look clunky and less defined.

Proportions

Proportions are often a matter of personal taste. In general, shapes that are too long and thin will appear malnourished, while shapes that are too thick and squat will appear clunky.

Long and thin shapes may also make a gemstone more fragile.

Rectangles with too close a ratio may start to look square. Generally, stones look more attractive when they have a distinct shape. Thus, a stone will look better as either a definite square or rectangle. An indistinct, in-between shape will detract from its appearance.

Ceylon sapphire ring - sapphire engagement ring stones
An unheated Ceylon sapphire with beautiful color, flanked by pear-shaped diamonds. The shape is indistinct, however, between a circle and an oval. © Urth Kandi Jewelry. Used with permission.
Standard Measurements

If you’re purchasing a sapphire for a custom ring, you should consider all the points above when evaluating the stone. However, if the stone needs to fit a pre-manufactured mounting, make sure the stone also has standard measurements. Otherwise, you’ll find yourself going beyond your budget to purchase a custom mounting.

Carat

Sapphire price per carat increases gradually as the stones get larger. However, at 5 carats, the price per carat really jumps.

What are the Best Money Saving Options for Sapphire Engagement Ring Stones?

Classic blue sapphires, from rich royal blue to cornflower blue, hold considerable value. Not surprisingly, sapphires often receive heat treatments to enhance this color. Even if heated, stones with these coveted colors tend to be expensive, especially in large sizes.

If you have your heart set on blue but need to stay within a budget, consider the following options.

Synthetic Sapphires

Synthetic sapphires will look the same to the naked eye as high-quality natural stones, but at a fraction of the price. Synthetic sapphires are real sapphires. They’re just created in laboratories from the same materials under the same conditions found in nature, only greatly accelerated. These stones have the same optical and physical properties as natural stones.

If you’re determined to buy natural sapphires, you should familiarize yourself with synthetics to make sure you’re not actually purchasing lab-created stones for natural prices. On the other hand, if your main focus is obtaining a quality sapphire, especially a blue sapphire, at a discount price, synthetics are a good option.

For more information on synthetic sapphires, check out our sapphire buying guide. For more information on the processes used to synthesize gems, see our article on identifying synthetics.

Doublets

Sapphire doublets usually consist of a thin slice of natural green sapphire glued to a synthetic blue sapphire. Despite how this may sound, doublets are harder to detect than most consumers imagine, even under a microscope. The synthetic blue bottom will color the entire stone blue, while the natural green sapphire top will contain natural inclusions. This will make the stone appear natural when examined from the top.

Usually, the easiest way to see if a sapphire is a doublet is to examine the stone from the side with backlighting. The top will appear green and the bottom blue. However, a thinly sliced green sapphire top may still be difficult to see. Gas bubbles may also form in a flat sheet between the two glued parts of the doublet, so you can look for these, too. Finally, if the bottom half of a sapphire is too clean and contains curved striae, while the top contains natural inclusions, the stone is most certainly a doublet. 

Doublets make affordable synthetic stone options. However, they do have special care needs due to their glue layer. If you want to avoid doublets, be sure to examine the stones before they’re placed in ring settings.

What to Avoid

Many gemstones receive treatments or enhancements of various types. For sapphires, for example, heating is a common and accepted practice. Untreated sapphires are very rare. Some treatments, however, aren’t recommended. Avoid buying fracture-filled and lattice diffusion treated stones. These treatments make gems fragile, and the enhancements won’t endure over time. They will also lower the value of the gemstones, so buyer beware. Some unscrupulous merchants may not disclose these enhancements. 

Ring Settings for Sapphires

At a 9 on the Mohs scale of hardness, sapphires can resist scratching better than all other natural gemstones besides diamonds. In addition, they have no cleavage and can have a tough tenacity, which means they also resist shattering from impacts. From a practical standpoint, sapphire is one of the best options for an engagement ring stone. (Because of this durability, some manufacturers use synthetic sapphire layers for watch faces and smartphone screens).

Jewelry makers can set sapphires relatively easily, whether faceted or cabbed. Most faceted sapphire engagement ring stones receive prong settings so viewers can admire the gem from all angles. (Vintage and Art Deco-inspired designs often place sapphires in bezel settings). 

Pears, hearts, and marquises need V-shaped prongs to protect their points. Square or emerald-cut sapphires often need prongs on their corners to prevent chipping.

Most prongs on the market today are short and rounded. However, long and pointed claw prongs have recently come into fashion. Claw settings can add a modern or edgy touch to an engagement ring.

White gold or platinum settings tend to give sapphires a clean, elegant look. Yellow and rose gold, on the other hand, will make the color of a blue sapphire stand out more.

sapphire and gold - sapphire engagement ring stones
Since yellow complements blue, the gold of this bracelet makes the blue of the sapphire look richer. © Urth Kandi Jewelry. Used with permission.

Caring for Your Sapphire Engagement Ring

How much care sapphires require depends greatly on their treatments. Untreated sapphires as well as those that only received heating are both stable and durable. These gems, as well as lattice-diffused sapphires, are fairly resistant to heat, light, and most chemicals. They can be cleaned in ultrasonic and steam cleaning systems.

Mild acids can damage fracture-filled or dyed sapphires. Clean these gems with damp cloths only. Boric acid can damage any type of sapphire, so keep your sapphires away from any solutions that contain it.

Lattice-diffused stones usually only have a shallow layer of color. Scratches or re-polishing can easily remove it. Treat these stones very carefully or their inner color will show through, giving them a messy look.

Sapphire Style

Traditionally, jewelers have set rich royal blue sapphires with diamonds in ornate settings. Recently, thanks to brands such as Le Vian, paler blue sapphires and even blue sapphires with slight greenish tints are coming into vogue. Marketed as “blueberry” and “denim” sapphires, these stones make great everyday rings in more casual settings. 

Lighter blue stones make affordable options for those who want a natural sapphire. These also have the advantage of being more brilliant than darker, classic stones.

For something very different, consider a cabbed sapphire or a color change sapphire for an engagement ring stone. Either option would be more affordable than a traditional stone.

blueberry sapphire - sapphire engagement ring stones
This 2.38-ct cushion-cut Ceylon sapphire demonstrates a sky blue or “blueberry” blue, as opposed to the traditional cornflower or royal blue. Photo by gemteck1. Licensed under CC By 2.0.

About the author
Phoebe Shang, GG
A gem lover and writer, Phoebe holds a graduate gemologist degree from the Gemological Institute of America and masters in writing from Columbia University. She got her start in gemology translating and editing Colored Stone and Mineral Highlights for a professor based in Shanghai. Whether in LA, Taipei, or New York, Phoebe spends her time searching for gems to design and being lost in good books.
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