Because of my job I get to look at a variety of natural fancy colored diamonds. Most of the diamonds I have looked at are truly beautiful. We pride ourselves on only selling the best of the best so it has to pass a variety of our criteria before we will purchase it.
Unfortunately, now and then a dud will cross my path. Because colored diamonds are so rare, when a poorly cut diamond is presented to me it can be disappointing to say the least. I want to love them all but sometimes they just don’t make the grade (pun sort of intended). In most cases though, it is a true treat to loupe a diamond and see the color, the brilliance , the fire and the unique beauty in the stones. And then there are the times when a diamond exceeds my expectations and is truly astounding and for some strange reason the image of the diamond stays with me many hours, even days after looking at it. (Occupational hazard I suppose.)
For me, it is “The Guildhall Blue”.
This diamond is a 1.06 Carat Natural Fancy Vivid Blue Internally Flawless Radiant Cut diamond. The reason I am writing about it here is because I was offsite looking at it the other day and it keeps popping into my head. Perhaps it was the astounding brilliance, the hypnotic patterns of light and dark when gently rocked back and forth, the intensity in which the spectral colors danced or was it knowing that I was looking at a blue diamond, something so rare and valuable? I suppose it was all of this combined, and like most natural wonders, it is a little awe inspiring and just has an inexplicable effect on a person!
According to both the GIA Grading Report and Independent Appraisal this stone does not contain underlying hues, nor does it have any fluorescence and the color is evenly distributed. Blue diamonds tend to include grey or brown hues but this diamond is pure, like diving into the most beautiful, pristine, clear blue glistening ocean. Ok, that was a bit cheesy but sometimes when I get so excited about diamond color it does get difficult to express without sounding sort of corny or way too analytical for most people to handle. The cut of the diamond, being a radiant maximizes the blue color which is even throughout the stone. Generally speaking, the more saturated the hue in a blue diamond, the rarer and therefore the more valuable it will be. As a matter of fact, statistics show that less than 0.3% of all colored diamonds graded by the Gemological Institute of America (GIA) in the first half of 1998 were predominantly blue. I am told that this statistic has not varied much since then.
This particular diamond comes from my father’s private collection but he has put it on our website in case the right buyer comes along – and then he may part with it. He has had it appraised a few times and it has gone up quite a bit in the last year alone. The latest appraisal which is the replacement value came in at $1.5 million. The appraiser we use tends to be on the conservative side with appraisals, but I think it’s better than being over-inflated. For more details about the stone, including the price, you can look at it here.
While I’m sure the image of the diamond will fade from my mind over the next few days only to be replaced by something new. I wonder what can possibly top this one?
So where do blue diamonds get their color from?
When boron, hydrogen or nitrogen particles get trapped in a diamond’s crystal lattice during formation it will turn blue or to be more specific variations of blue, from teal, to ice blue, to grey blue to pure blue. The higher the quantity of boron impurities found in a diamond’s lattice structure, the more saturated or intense the blue color in the diamond will be.
Type IIb diamonds account for approximately 0.1% of all Natural Fancy Colored Diamonds, holding minute amounts of nitrogen and significant levels of boron impurities.
Green-blue or greenish blue (think teal) colored diamonds typically contain nitrogen impurities in aggregate form. The degree of color returned to the eye is dependent on the amount of nitrogen included in the stone.
Some blue diamonds include the presence of hydrogen impurities. These type Ia diamonds are generally classified with a color modifier and predominantly referred to in gemological grading reports as gray-violet or gray-blue.
How are Blue Diamonds Graded?
The diamond industry uses the universal GIA Color Grades with a worded description of the actual hue (the color) i.e. Purplish Blue in order to keep colors consistent and easily understood because my interpretation of sky blue may be different to yours. This cuts out any confusion.
The GIA uses nine categories to grade colored diamonds which are: Faint Blue diamond, Very Light Blue diamond, Light Blue diamond, Fancy Light Blue diamond, Fancy Blue diamond, Fancy Intense Blue diamond, Fancy Vivid Blue diamond, Fancy Dark Blue diamond and Fancy Deep Blue diamond.
Where Did “The Guildhall Blue” Name Come From?:
Just in case you might be wondering why I’m calling this stone “The Guildhall Blue” it’s because we have 2 blue diamonds posted on our website and people inquiring about this particular stone started referring to it as “Your Guildhall Blue” to differentiate it so the name sort of found its way into our hearts.