Buying a sapphire is much less technical than buying a diamond. Diamond's are treasured for their brilliance while sapphires are loved for their color. Since it's all about the color, you need to buy your sapphire from a website that has high quality images of their stones, if you want to buy online. Not only do reputable jewellers offer loose gemstones, but they make stunning jewellery with 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 jewellery.
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 name sapphire comes from the Greek word "sappheiros" or the Latin word "saphirus", both of which means "blue". 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. This deep blue gemstone has been adored for its color. durability and beauty since ancient times.
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.
Like diamonds, sapphires take millions of years to form, and no two natural sapphires will ever look the same. They are formed beneath the earth's surface under immense pressure and intense heat out of the mineral called corundum (aluminium oxide) which seeps into cracks in igneous or metamorphic rocks.
Once the liquid cools, it turns into colorless crystals. However, when minuscule traces of other minerals (often as little as 1%) mix with corundum, they turn it into various colors such as red, pink, blue, yellow etc.
If the transition microelement is iron or titanium, the corundum turns blue and we get blue sapphires. In the case of chromium, the corundum turns red and gives us rubies. The other sapphire colors are caused by various mixes and proportions of iron, titanium and chromium.
Most corundum in nature is heavily included, suitable only for industrial us, while gem-quality corundum is very rare. Rough sapphires come in a barrel shape that is tapered at the ends and larger in the centre. Once mined, they can be cut into any shape and used for jewellery manufacturing.
Sapphire deposits can be found in Madagascar, Sri Lanka, Myanmar, Thailand, China, Australia, Nigeria, Pakistan, Kashmir, Nepal and the United States. Depending on the location they come from, sapphires can have different chemical properties and inclusions. Gemstones from Kashmir, Burma and Sri Lanka are the most prized due to their high quality and clarity.
When corundum takes on a color other than red, the gemstone is typically classified as sapphire, meaning there are many color varieties in sapphires. While the "official" color of this gemstone is blue, the other colors such as pink, purple, green, orange and yellow are sometimes referred to as "fancy sapphires". However, this term does not apply to the colorless, black and blue specimens.
When iron present in the chemical composition, the sapphire takes on a yellow color. When vanadium - sapphires get purple, and the best-known blue sapphires are created if iron or titanium is present in their structure.
Burmese and Kashmir sapphires usually have an intense and velvety blue color: however, these stones are very rare nowadays. Today the most common sapphires are the ones from Sri Lanka and Madagascar that come from light to dark blue color.
Color is the most important attribute of a sapphire. The closer a sapphire is pure blue the better, but saturation is also important. The top sapphires reach vivid saturation (pure royal blue) as most of the gems on the market are grayish. The tone is another important consideration. Dark sapphires are much in the market but they never reach very high values.
In general, the intensity of blue is the most important factor with blue sapphires, meaning a big stone that has a washed-out blue color will always cost less than a small vivid blue stone.
The most desirable sapphire color is the intense cornflower blue that is not too dark. In general, stones that have too dark or too light color are not that valuable. However, light blue stones have greater brilliance than darker ones.
Another highly-priced and possibly the rarest specimen is the Padparadscha sapphire, named after a delicately colored lotus flower. It is a unique blend of pink and orange sapphire resulting in a stunning peachy or salmon color.
There are also color-change and bi-colored sapphires, which are exceptionally rare. The ability to change color when viewed under different types of light is a rare phenomenon in the world of gemstones. However, some sapphires display a bluish color in daylight and reddish color under electric lights. Bi-colored sapphires display two different colors under the same lighting conditions.
Let's take a look at the 4Cs of sapphires in their order of importance:
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.
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.
Whereas diamonds have an elaborate, standardized color grading system, sapphires and other colored gemstones have no such similar way to assess 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 to use your own judgment about which colors appear vibrant and alive to you, or use the preferred grading system described below. 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 jewellers.
Sapphires are gemstones. Therefore, they can be graded by the preferred grading system for all gemstones: Natural AAA, AA, A, and B:
Natural AAA: This grade accounts for just 2% of all natural gemstones.
Natural AA: This grade represents 10% of all natural gemstones available in the world.
Natural A: This grade forms the top 20% of natural gemstones .
Natural B: This category accounts for over 50% of natural gemstones.
The most important characteristic to consider when determining a sapphire's price is always its color grade. The best color for a natural blue sapphire is an intense, velvety, deep royal blue. This color of sapphire would be considered AAA quality, the rarest and most valuable. The second best color is a medium rich blue, or AA quality. Any blue sapphires that have a slight gray undertone fit into the A category. Finally, sapphires that have a very dark and opaque blue color are considered B quality grade. The 3 keys to color grading are identifying hue, tone and saturation. Color is graded on these factors face up on a white surface. The hue should be royal blue, the tone should be deep blue and the saturation should be even throughout the gem.
Although both sapphires and rubies are formed in a similar mineral structure, sapphires often have better clarity. They can come transparent to opaque, transparent stones being the most valuable.
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 guide 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.
Sapphires can come with several types of inclusions such as needles (fine needles are called silk), mineral crystals, feathers, partially healed breaks that look like human fingerprints and color zoning. Each of these inclusions has a different impact on the stone's sparkle and light performance.
In general, inclusions make a sapphire less valuable. The price can drop significantly if the inclusions affect the stones durability. However, inclusions can also increase the value of some sapphires. The most valuable Kashmir sapphires contain tiny silk inclusions that give them a velvety appearance.
A variety of different inclusions can form within a natural sapphire. Each has different implications on the gemstone's visibility and sparkle or light performance. Inclusions can typically be seen with the naked eye, while others can be seen with a 10x microscope.
While the appearance of inclusions are not usually regarded as positive, in the case of asterism, the opposite is true. The same silk causes phenomenal asterism in star sapphires. 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.
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.
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 1.00 carat sapphire will look smaller than a 1.00 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 1.00 carat sapphire generally measures 6 mm.
Sapphires come in size range from few points to hundreds of carats. However, the most popular sizes are less than 5.00 carats.
Fine-quality big stones are very expensive. For example, a 5.00 carat fine-quality blue sapphire can cost five times more per carat than the same quality 1.00 carat stone. This example is not meant to be an exact price guideline, but to illustrate how much the price-per-carat can go up as the quality and size rise.
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.
It is worth mentioning that the shape of the sapphire rough has a great influence on the shape and size of the finished stone. Since rough sapphires usually come in a barrel shape, the finished stones are often deep. To achieve the best overall color, proportions and minimal weight loss, cutters also have to focus on color zoning (areas of different colors in a stone). For example, blue sapphires have zones of lighter and darker blue, so cutters have to concentrate color in a location that is best visible in the finished stone.
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.
You can find treated sapphires that look nice. But the color just doesn't look quite the same. 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.
Most reputable jewellers offer consumers only the highest quality, authentic gemstones. Their colored gemstones undergo rigorous internal inspections by trained gemologists to ensure they meet stringent quality standards.
Due to their rarity and unique visual properties, nearly all colored gemstones sold at reputable jewellers, are enhanced using various techniques. Many of these techniques have been used for centuries. Colored gemstones that have not been enhanced are very rare and command extravagant prices.
While colorless and fancy color diamonds are not enhanced in any way, other than normal cutting and polishing. Black diamond fashion jewellery contains natural diamonds that have been treated to create the unique black color.
Untreated sapphires are the most rare and expensive types. They are less than 1% off all the sapphires that are found in the world:
Heated Sapphires: Sapphires are heat treated to improve both their color and clarity. Heat treatment is a natural process that is similar to the intense heat that sapphires experience while forming within the earth. No chemicals are a part of this process, and no foreign materials enter the sapphire. The improvement in clarity and color for the sapphire is permanent. As this is a natural treatment, it is widely accepted and used for sapphires used in jewellery.
Beryllium Treatment: This is a process involving beryllium which are introduced to the sapphire and penetrate it. Through this treatment, the color of the sapphire is enhanced and saturated further. It can be used to intensify the colors of orange, yellow and other lower-grade sapphires.
Surface Diffusion: In this treatment titanium is used to coat the sapphire so that the color and the brilliance is enhanced. The treatment does not penetrate as deeply as the beryllium treatment. Repolishing the stone later may remove part of the chemical enhancement and lighten the color.
Cavity Filling: In this treatment, cobalt infused glass is used to fill cracks and fissures that are from the top of the sapphire through within it. The glass fills the cavities in the sapphire and the cobalt retains the blue of the sapphire.
|Chemical Name||Aluminium oxide|
|Crystal System||Hexagonal and trigonal|
|Colors||Blue, pink, purple, yellow, green, orange, colorless, grey. black and multicolored|
|Hardness||9.00 on the Mohs scale|
|Refractive Index||1.76 - 1.77|
|Specific Gravity||3.98 - 4.06|
|Transparency||Transparent to opaque|
|Lustre||Vitreous to adamantine|
|Cleavage||None, but may exhibit parting|
Techniques for enhancing colored gemstones, either detectable or otherwise, are continually being developed. These may be difficult, or in rare cases, impossible to detect, even for the most sophisticated laboratory. Reputable jewellers will continue to work with industry groups and gemological experts who are committed to the identification and disclosure of new and future techniques in order to maintain stringent quality standards.
While gemstones are durable, they require varying levels of care. For example, some gemstones are especially vulnerable to household chemicals and temperature changes. Cleaning gemstones presents special challenges. While many gemstones should be cared for by following our basic care guidelines below:
Cleaning: After removing your gemstone jewellery, clean it by following the directions on a non-abrasive jewellery cleaner. Make sure that the jewellery cleaner specifies that it is safe to use with your gemstone. Use a soft cloth to remove any remaining dirt or other residue.
Storing: Store your gemstone jewellery in a lined case or a soft cloth, so the gems do not touch each other or parts of other jewellery. Gemstones are harder than gold, silver, or platinum and can scratch the surfaces of your other fine jewellery if they are not kept separate.
Wear: While it's true that gemstones such as ruby and sapphire are second only to diamond on the hardness scale, it is not a measurement of their indestructibility. It means that these gemstones are able to resist scratching almost as well as a diamond. Abrasive surfaces, harsh chemicals, and sharp blows can damage even the hardest gem. Your gemstone jewellery should be the last thing you put on when getting dressed and the first thing you take off at the end of the night. Store your gemstones carefully and they will be enjoyed for generations.
When you're buying a sapphire, it's essential to see a high quality image of the stone for yourself, if you are buying online. 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.