Sapphire Gemstone Guide – Price, Quality Factors & More!
If you clicked on this post, then I’m guessing you want to learn more about Sapphires?
Awesome, you have come to the right place as my Sapphire Gem Guide takes you through what you need to know about these amazing stones, whether you are looking to buy one or just looking to learn, so let’s get started…
Sapphire Properties
Let’s start with looking at some of the chemical, physical and optical properties of Sapphire:
These are important to know as they can help with identifying whether a stone is a Sapphire or not but I’ll cover that later.
Sapphire Formation and Origins
The majority of Sapphires form in one of two ways, which are:
But in order for a Sapphire to form, the environment has to be aluminium-rich and devoid of silicon.
Some Sapphires can also be formed by hydrothermal processes, where molten, mineral-rich solution flows through cracks and fissures in the Earth’s crust, over time, this solution begins to cool and as it does, Sapphire crystals begin to grow.
In order to get all the colours that Sapphire comes in, there does need to be some additional ingredients (the correct term is trace elements), as in their purest form, Sapphires are colourless and different colours are caused by different elements, including:
Where Are Sapphires Found?
Sapphires are found in many countries around the world, including:
Sapphires are found in many other countries but these are the most important locations, with the majority of the world’s Sapphires coming from these locations.
Sapphire Price
Sapphire prices can vary massively from less than $20/carat to over $100,000/carat due to the large number of factors that affect the price of a Sapphire, including:
This makes pricing Sapphires quite challenging, which is why this is done on a stone-by-stone basis by people who understand the Sapphire market and makes it nearly impossible to give any kind of guide to Sapphire prices online.
In the Sapphire Quality Factors section below, I will look at some of these sections in much more detail and explain how these factors impact the price of Sapphires.
Sapphire Quality & Price Factors
Now we know what Sapphires are and where they come from, let’s take a look at the quality and price factors as these all play an important role in how much a Sapphire is worth!
Sapphire Colour
Arguably the most important quality factor for Sapphires is the colour and when talking about colour, there are two different things to consider, which are:
The Different Colours of Sapphire
As I mentioned earlier, Sapphires come in a range of different colours and when it comes to value, some colours are more valuable than others due to the demand and availability of that colour in the market and generally:
This mainly applies to Western markets but in some markets, Green and Yellow Sapphires are much more in demand than Pink or Purple stones.
Quality of the Colour
The second part is the quality of the colour as this has a big impact on the value of a Sapphire and applies to all body colours.
Very good quality Sapphires have a rich, vibrant body colour with good hues and saturation that is spread evenly across the stone, with lower quality stones either being very light or dark or having an uneven distribution of colour across the stone.
The image above demonstrates this perfectly as:
One thing that can be quite commonly found in Sapphires is angular colour zoning as can be seen in one of my rings.
Colour zoning is bands of colour that range from blue to colourless in Blue Sapphires, these are visible in the stone and may only be visible from certain angles, depending on how they have been cut.
These are not as desirable as Sapphires that have an even colour distribution but it is an indication that the stone is natural and it does add character.
Sapphire Clarity
Clarity is another important quality factor when it comes to a Sapphire’s price, with the most desirable stones being:
Having some inclusions in a Sapphire isn’t always a bad thing, as inclusions can help gemmologists identify a potential origin and whether the stone has been treated or not.
While the majority of the time, most people will be looking for an ‘eye clean’, transparent Sapphire, there is one exception to the rule!
And that is Star Sapphires, which are heavily included, opaque Sapphires that show a phenomenon known as asterism, which you can clearly see in the GIA picture.
The Asterism is caused by lots of rutile needles within the stone that follow the growth structure of the natural crystal and when the stone is cut properly, the light reflects off these inclusions to cause the appearance of the star.
These are highly desirable among collectors.
Sapphires Are NOT Clarity Graded
Unlike Diamonds, Sapphires are not clarity graded by gemmologists or gem labs, so be aware of anyone selling a Sapphire who is using Diamond clarity grades such as SI or VVS to describe the clarity of a Sapphire.
Sapphire Treatments
Whether or not a Sapphire has been treated or not plays a big factor in the stone’s value.
This is because Sapphires with good colour and clarity are very rare in nature and there is nowhere near enough of these stones to satisfy the demand for them, which is why they attract a premium.
It is estimated that over 90% of Sapphires for sale at any one time have been treated in one way or another and there are a number of different ways that Sapphires can be treated, all of which have an impact on the value of the stone, these include:
Heat Treatment
By far the most common treatment method is heat treatment, the outcome of heat treatment depends on the stone but results can include:
Heat treatment replicates what happens to stones in nature and the results are permanent.
It is an industry-accepted treatment and is rarely disclosed, as it is assumed (especially for Blue Sapphires) that the stone has been heat-treated.
Sellers will explicitly state if a Sapphire hasn’t been heat-treated but should always have a report from a reputable lab to confirm this.
Heat-Treated Sapphires sell for less than their untreated counterparts and as the majority of Sapphires on the market have been heat-treated, a lot of pricing is based around heat-treated stones
Heat Treatment + Flux
A modification of the traditional heat treatment is to add a flux (usually borax) to the process.
The result of this treatment is that can help to partially ‘heal’ surface-reaching fractures by melting and recrystallizing the surface of the fracture, which makes them less noticeable.
As with standard heat treatment, the results are permanent but it should always be disclosed.
Heat + Flux Sapphires – these sell for less than Sapphires that have just been heat-treated due to the additional treatment that has taken place
Diffusion Treatment
A treatment that is becoming more common is diffusion, this is where they heat the Sapphire to a very high temperature in the presence of either Titanium or Beryllium to alter the colour of the stone:
Full disclosure is required for all diffusion-treated Sapphires.
Diffusion-Treated Sapphires sell for less than stones that have just been heat-treated
Glass Filling
Glass-filling is done to very low-quality material with the goal of filling the fractures with lead-glass (which has a similar RI to Sapphire), which reduces the appearance of fractures, making them more attractive to look at.
The process of glass-filling involves heating the stone in the presence of lead-glass powder, which melts and fills the fractures.
Glass filling isn’t a permanent treatment and can easily be removed from the stone (such as being exposed to the heat of a jeweller’s flame) and should always be disclosed.
Glass-filled Sapphires sell for less than $50/carat as they are very low-quality, in some cases they are more glass than Sapphire and should be avoided
Natural vs Synthetic (Lab-Grown) Sapphires
The nature of a Sapphire has a HUGE impact on the value as there is a huge price disparity between natural and synthetic Sapphires (not including glass-filled ones!).
For example, the synthetic Sapphire in the image above can be bought for less than $10/carat but a natural of the same size and quality would easily be over $1000/carat and could be over $10,000/carat if it hasn’t been treated.
If the stone is being sold as a Sapphire, then it is assumed that the stone is natural as all synthetic stones state that is synthetic, man-made or lab-created so that you as the buyer know that it isn’t a natural Sapphire.
Sapphire Weight
The weight of the stone will also have an impact on the value and the reason for this is that larger stones with good colour and clarity are rarer and more desirable than smaller stones (this applies to untreated and heat-treated stones) and sell for a higher price-per-carat.
There are also certain weight thresholds (I can’t think of a better word) where the price-per-carat can jump significantly and these include:
Sapphire Cut
The next quality factor is cut and just like colour, this is broken down into two parts, which are the style of the cut and the quality of cut.
Style of Cut
The majority of natural Sapphires on the market are usually cut in one of four styles, which are:
- Oval
- Cushion (including elongated cushions)
- Round
- Emerald or Hexagonal
This is because these styles not only help bring out the stunning colour found in Sapphires but also produce the best yield from the rough crystal from which they are cut.
But Sapphires can also be cut into Marquise and Heart shapes but the demand for the styles of cut are quite a bit lower than the four popular cut styles.
Quality of Cut
Not all Sapphires are cut to the same quality, this usually isn’t an issue with more expensive Sapphires as the cutter takes more time to make sure the stone is cut and polished to a high standard as the stone will be worth more as a result.
But this can be an issue with lower-quality Sapphires and can result in:
- Poor proportions such as the crown or pavilion being too deep or shallow
- Facets not being aligned properly
- Table being off-centre
- Wonky girdle
This can make the gem not look as good as it could if it had been cut properly and it also makes setting the stone into a piece of jewellery more challenging for the setter.
Lab Reports
Lab Reports are an important document but not every Sapphire will be sold with a report as unlike Diamond reports, they don’t give any information about the quality of the stone but they do include some very useful information, which can include:
- The stone, size, weight etc
- The identity of the stone
- Whether the stone is natural or synthetic
- If the stone has been treated or not
- The origin of the stone (it is not possible to do this on some stones)
And a report from a reputable gem lab, such as the GIA, Gubelin, SSEF, IGI or Anchorcert is essential if the seller is claiming that the Sapphire is untreated and from a specific location.
Reputable Gem Labs ONLY Produce Reports
And they explicitly state this on the document/card that accompanies the stone, if the document or card says ‘certificate’ or ‘certificate of authenticity’, run away from it as fast as you can as the stone might not even be a Sapphire.
How To Identify A Sapphire
I always recommend getting a stone checked by a qualified gemmologist or gem lab to be sure on the identification of a stone, especially ones with potential to be worth a lot of money, like Sapphires.
There aren’t any easy, at home tests and electronic testers aren’t exactly reliable.
My process for identifying Sapphires is:
I don’t use any other standard gemmology tools as Sapphires do very little on any of them and I don’t own any advanced tools.
Once I have identified that the stone is a Sapphire, my next step is to see if it is natural or synthetic and this is done by taking a closer look inside the stone:
Flame-fusion synthetic Sapphires are pretty easy to spot but flux-melt ones can be challenging as they can appear very similar to natural stones, so more care needs to be taken to understand the inclusions within the stone.
Sapphire Gemstone FAQ
Conclusion
I know that this is a bit of a long guide but I wanted to provide you with as much information as possible so that you can buy the perfect Sapphire for yourself or the person you plan on giving it to.
And by educating yourself around Sapphires, you can make a more informed buying decision that will hopefully result in you getting the perfect stone and not overpaying for it.
Other articles from The Gem Guide series:
I'm Paul Haywood FGA DGA, the owner and founder of Haywoods Gems, I'm a fully qualified Gemmologist and Diamond Grader from the Gemmological Association of Great Britain.
