Why are fine-quality, natural blue sapphires so exclusive?
In this post, I’ll share some features that many blue sapphires tend to have and which explain why it’s so hard to find a natural, untreated blue sapphire of high quality.
White 18-karat gold ring with a 7.05-carat pear shaped Blue Sapphire from the High Jewellery collection "Extremely Piaget”.
However, as you may remember from another blogpost, I also told you it’s quite rare to find that exquisite and uniform colour blue in nature. In fact, each facet (which is the small surface on a cut and polished gemstone) of a blue sapphire may show some variations on the gem’s key colour. Some facets may appear bright, some dull, some dark-toned, others lighter-toned.
This multi-colour effect in blue sapphire has several causes:
firstly, sapphire is “di-chroic” which means that light entering the gem is divided into 2 rays:
- a violetish blue and
- a greenish blue ray.
And also, sapphire is often “colour-zoned” which means that colourless or white bands are lying next to zones of blue colour. This is totally natural and normal to find.
However, these features create a negative effect in blue sapphires in the form of what is called “bleeding”. This bleeding is particularly evident when you bring the stone from natural light to incandescent light (i.e. under a lightbulb). This often causes a lightening of the tone and a loss of saturation! So the blue basically can become lighter and washed out or it can become a bit more murky.
Of course, not something we want.
But keep in mind that any gemstone has its pros and cons... including the blue sapphire and yes, even the diamond is not sacred. They all have their instructions of care and special characteristics to be aware of.
This is precisely why I like them so much and also what will (hopefully) make you appreciate their intrinsic beauty and value even more. Because when you do see a blue sapphire that doesn’t suffer from that bleeding feature (or not so much), you understand how special it is. And a premium will be attached to that.
Now there is actually one blue sapphire that has a natural defense mechanism against this bleeding feature... That’s the Kashmir blue sapphire. Another legend. Like the Burmese ruby. With an equally nice price tag attached. (Though typically lower than ruby).
But I’ll tell you more about the Kashmir blue sapphire hero in another blogpost.
The cutter blues...
So a lot of blue sapphires have to deal with these inherent issues of dichroism, colour-zoning and also greenish components that are often found in the colour of blue sapphires.
Quite a complex lady she is.
And so it’s nice to know that there are people out there who actually know how to deal with her and bring out her very best assets. This is where the stone cutters help us out with their high level of craftsmanship and skills, often obtained over decades of experience.
It is the cutter’s job to cut the stone in such a way that all these negative elements, such as that greenish colour component, the colour-zoning and dichroism are avoided as much as possible in the final face-up appearance of the stone.
So that when you look at the stone as it's supposed to be looked at - in its face-up position - you'll see the blue sapphire at its best... Without any hints of green nor any of that dichroism or colour-zoning going on. That’s the cutter's responsibility.
As you can imagine, you need an experienced cutter for that.
Interestingly, because of all these features a sapphire cutter needs to be aware of, sapphires regularly appear with cutting faults, like an off-center culet (the point at the bottom of a gemstone) or they can be lopsided ('bellied') below the girdle.
These cutting faults are quite normal and much more tolerated in a sapphire than most other gems. (For instance, in a diamond, those cutting faults would be considered really big flaws! But less so in a blue sapphire). Because it's simply practically impossible to find a blue sapphire in nature without any of those above-mentioned features. They are almost always present in a blue sapphire and so it's very hard for a cutter to cut away or around all those flaws perfectly.
Thus, it becomes a matter of rarity. And there’s more...
Besides having a good cutter trying to alleviate some of blue sapphire’s issues, there is another solution. And that is heat treatment. I won’t go into the details of heat treatments here but know that about 90-95% of blue sapphires in the market - just like ruby - are heated! To improve their colour and clarity.
It’s a totally acceptable treatment for blue sapphires. This does mean though that natural, unheated, blue sapphires can sell at a premium of approximately 30-50% (or more) above the price of a similar, heated stone.
All this brings me to the point of exclusivity and rarity:
So, when you do encounter a fine blue sapphire that is of good colour, has a good cut, is not treated and on top of that, is quite big, prices go up. Very quickly. Purely a question of the market demand being far bigger than Mother Nature can supply.
For example, I had a client who asked for a blue sapphire, of 5ct+, unheated, in a good blue and nice modern cut: it took me more than 6 months to find one of the quality I wanted which we mounted in the bespoke ring that you see here below…
Magnificent blue sapphire set in an intricate bespoke ring design.
But luckily, it is still possible to find blue sapphire in the world up to 8 or 10 carat (though rare!).
Finally, to give you some idea of what all this does to a blue sapphire’s price:
The Jewel of Kashmir: the priciest blue sapphire to date… I prefer the other brighter blue hue above, but I’m picky.
The most expensive sapphire to date is the 27.68 carat Kashmir blue sapphire you see in the picture above which sold in Hong Kong's Sotheby's Magnificent Jewels & Jadeite Auction in 2015 for $6.7 million… that is approximately $242,000 per carat!
Definitely less than the most expensive ruby auctioned to date but, you know, not cheap.
I hope the above helps you on your gemstone piece journey and if you need any help in sourcing a special coloured gemstone (like a fine blue sapphire) or with creating your own bespoke gemstone ring, set up a complimentary consultation with me below!