A Guide on Judging Quality in Blue Sapphires

Sapphire is one of the most significant gems in the world of precious stones. Many would be surprised to know that sapphires come in a wide variety of colours, with the most popular ones being red sapphire (also known as ruby) and blue sapphire. Other types of sapphire include pink, purple, yellow etc, but it goes without saying that right and blue sapphire are the most prominent gems in this category.


This beautiful blue gemstone comes with a very rich history and legacy, giving it pop cult status all around the globe. Associated with royalty, it is a symbol of abundance, hope, faith, energy, and spiritual clarity.


On a mineralogical level, blue sapphire is a highly precious blue gemstone of the corundum mineral family. It goes without saying that colour had the most impact on the value of blue sapphire. As such, the most coveted blue sapphires have a vivid and glorious blue colour saturation, ranging from velvety blue to violet-blue. These high-quality blue sapphires earn the bragging rights of claiming the highest price in the market.


It goes without saying that the market presents a wide range of blue sapphires that are complemented with an equally diverse variety of prices, spanning both relatively lower and high-end costs. You need to make sure that you are getting the right custom-cut sapphire of the highest quality for yourself and are not getting ripped off.


When you go to the jewellery store to get yourself a sparkling new blue sapphire, we want to make sure that you get nothing less than the best. That is exactly the premise behind this blog. We highlight the main parameters that would help you in judging the quality of blue sapphire and ensure that you get the finest piece(s) that suit your budget, needs, and lifestyle.


The four primary parameters that adjourn the value of blue sapphire are:


✓ Colour


✓ Clarity


✓ Cut


✓ Carat size


Let us check out each parameter in detail and help you understand how you can pick the best blue sapphire by taking careful consideration of each parameter.




Colour is quite possibly the most defining factor for blue sapphire. As the undisputed leader of the blue gemstone market, good quality blue sapphire is expected to exhibit its blue hues in all its grace and grandeur. That being said, blue sapphire comes in many shades of blue, each special in its own way.


But this begs the question: which shade of blue is the most desirable in a blue sapphire piece? Thankfully, we do not need to look for subjective answers as the gem industry itself has an answer to this pressing question. So technically, the gem industry, in general, considers a saturated royal blue as the premium colouration of blue sapphire. It is worth noting that 'saturated royal blue' refers to a deeply vivid blue with a violet undertone.


Now you are bound to be confused about what exactly is meant by the term 'saturated' in terms of gemstone colour. Well, saturation in a gemstone is referred to the intensity and purity of a gem's hue or colour. So a gemstone that lacks greyish or brownish shades is said to be strongly saturated and is considered more valuable than a gemstone with low saturation.


All blue sapphires display colour zoning when subjected to magnification. Zoning is an exclusive property of the sapphire family. The term 'zoning' refers to the appearance of uneven strips of colour in the sapphire. A fine-quality sapphire will display minimal zoning characteristics. In other words, zoning happens when the intensity or purity of colour is non-uniform in a gemstone. So if you find more colours on one side but less on the other side of the gemstone in question, the price should go down.




The concept of clarity is more or less a given when it comes to judging gemstones. While most are aware of clarity in diamonds, it is a different ball game altogether when it comes to coloured gemstones. You see, diamonds and coloured gemstones are never designated as flawless.


Even the highest clarity of blue sapphire (known as 'eye-clean') may have appreciable inclusions. However, they are not visible to the naked eye. It is worth noting that an eye-clean blue is hardly ever practical because even the best quality of these gems have some inclusions that are indeed visible to the naked eye. Inclusions are, however, considered natural in blue sapphire. In fact, sapphires are considered stones that can be categorized as "usually included" in terms of inclusions. Interestingly, tanzanite offers better clarity than blue sapphire and is more common with regard to the 'eye-clean' standards.



The concept of "eye-clean" does not mean that there is absolutely nothing visible to the naked eye. Rather there is a standard definition for this term in the gem industry: When viewed by a person with normal 20/20 vision, from 10-12 inches away, with the gemstone face directed towards the viewer, under an environment of diffused lighting, the gem will not have any visible inclusions.


It is worth noting that 10-12 inches are generally the distance from your eye to the surface of a table when seated at it, the way gem experts view pieces of precious stones. The orientation is the way the blue sapphire is mounted on the table.


Let's discuss some of the important factors pertaining to the clarity of gemstones:




Inclusions are characteristic "flaws" that are embedded or included inside a gemstone during the phase of its formation. In fact, the inclusions are generally due to materials that are even older than the gem per se. It is important to note that these "flaws" can be another mineral, liquid or even gas. These are essentially unique features of a gemstone and give them a sense of uniqueness.


Now, just how important are inclusions? Are they undesirable, or do they add some value to the sapphire?


Inclusions are essentially like birthmarks that bring a sense of uniqueness to each stone. In fact, microscopic inclusions are a sign of authentic and genuine blue sapphires. They are considered a basic part of any blue sapphire. Also, some inclusions are an indication of heat treatment. However, too many inclusions visible to the naked eye will bring down the value of the blue sapphire in question. After all, prominently visible inclusions are said to lower the beauty of the gems.




When the inclusions appear to be ultra-fine needle or string-like, they are referred to as "silk." This is attributed to the fact that this arrangement of inclusions looks like a fine weave of fabric when viewed under a microscope.


It is worth noting that this silk intercepts the incoming light and scatters it within itself. While this doesn't give high clarity, the optical interactions of the ray of light with the silk cause brilliance, making the sapphire shine!




The cut of a gemstone is another crucial parameter in adjourning the quality of the blue sapphire. All those facets in a gemstone come with a lot of intricacies behind them! In order to make the blue sapphire look gorgeous, the facets are created by taking into consideration the refractive index, reflection of incoming light, the correct critical angles, and display of colours. In fact, sapphires cut specifically for weight will lead to issues such as extinction or an underwhelming window. Let's find out more about these two topics.




To understand extinction, you need to know what extinction is not. It isn't when a facet of the gemstone appears darker than the other sides. Rather, it's when the dark spots appear lifeless. This is from poor cutting practices that lead to light not being reflected back to you. Thus, the gemstone will appear dead or extinct.




If you are able to see completely through the gemstone with the colour and facets appearing only along the edges, then this phenomenon is known as windowing. This happens when the angles at the bottom of the gem are cut lesser than the critical angles pertaining to the gemstone. So instead of light refracting and reflecting throughout the stone, it simply goes right through it. Needless to say, poor cutting practices would lead to a bad-looking window.


It is worth noting that a little bit of window can be offset through mounting of the gemstone due to the lack of backlighting. In some cases, small windows are left behind intentionally, even in good gemstones, in order to bring them closer to the desired carat weight. In other words, a small window can add a few decimals to the numerical value of the carat weight.


Blue sapphires come in various shapes, but the usual ones include the round and oval shapes as they optimize the natural shape of the raw material. Raw material can be cut to a gemstone that would weigh only 1/3rd of the original weight when intended for beauty and not size. A skilled gemstone cutter can achieve this.


Unlike diamonds, sapphires have to be cut in specific ways in order to bring out the colours in all their glory and optimize the reflection of light to the maxima.


If you are looking for a high-quality sapphire, then it should have been cut for beauty and not for weight or size. Needless to say, a top-notch blue sapphire should not have rough edges, chips, indentations, or poor polishing.


To sum it up, a blue sapphire cut properly by a skilled cutter will maximize the stone's appearance and brilliance.


Carat size


The carat size or the weight is perhaps the least significant of all the quality parameters. It is important to understand that in the case of sapphires, the "face-up" dimensions are the crucial measurement and not the carat weight.


Just like how every gemstone has a unique refractive index that governs the reflection of light within the crystalline structure of the gem, they also have a physical property known as weight. And coloured stones are priced per carat and are a function of the size of the blue sapphire. So the bigger the size of the blue sapphire is, the more expensive it will be. In other words, larger coloured gemstones are more difficult to come by, and when they do, they are naturally priced higher.


Get the blue sapphire of your dreams at Iris Gems.


When it comes to the complete look and feel of your blue sapphire, we at Iris Gems have a lot of options. For instance, if you are interested in the shape of your stone, we have several options, including:


  • Brilliant
  • Oval
  • Cushion
  • Heart
  • Pear
  • Emerald cut
  • Baguette
  • Square
  • Princess
  • Radiant
  • Briolette
  • Trilliant
  • Marquis


It is important to note that these are just the traditional shapes of our blue sapphires, but we also offer customization! We offer cuts that are tailor-made to suit your needs while ensuring that you get the highest quality of gems.


During your blue sapphire purchase, you would want to be confident of your choice by examining your stone as well as you can. The four quality parameters highlighted in this write-up would make you a more educated customer during the purchase of any gemstone (not limited to blue sapphire alone). Iris Gems will make sure that your gemstone ticks all boxes of quality, and you get only the best!


We understand just how important a gemstone is to you, and we will leave no stone unturned in ensuring that you are happy with your purchase. Therefore, we have professional photographs of every single stone we sell, not just a stock photo. This way, you can rest assured that you are getting a thorough, accurate, and comprehensive visualization of your precious stone. Our penchant for high quality and exceptional customer service have made us the go-to destination for purchasing the best gemstones.


At Iris Gems, we come with the right blend of expertise and experience in helping people find the perfect precious stone that fits their needs, budget, individuality, and lifestyle. So get in touch with us or book an appointment, and we promise you the finest blue sapphire that you would fall in love with.