Medium Blue or Strong Blue Fluorescence in H Color Diamond?

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December 2

Hi Todd, I’ve been reading your blog for several weeks and have found the information which you provide to be extremely helpful. I’m trying to select the best option between two diamonds cut by Brian Gavin.

One is an H color diamond with medium blue fluorescence and an H color diamond with strong blue fluorescence. I’m hoping you can help me select the best option. I am also intrigued by the idea of blue fluorescence. However, I have heard mixed reviews about strong blue fluorescence.

I plan on having the diamond set in the platinum Tiffany knife edge style solitaire from Brian Gavin (pictured left) I appreciate any insight which you can provide — Frank C.

Thanks for your inquiry Frank, I’ll run through the details for the diamonds from Brian Gavin below that you referenced in your email. I have seen the knife edge Tiffany style solitaire from Brian Gavin in person and think that it is a stunning classic engagement ring. I really like the prong configuration, which reminds me of a crown… it is one of my favorite styles of traditional solitaire style engagement rings.

Brian Gavin Blue Diamonds with Fluorescence:

The two options which you selected from the Brian Gavin Blue collection of diamonds with blue fluorescence are described as follows:

1.216 carat, H-color, VS-1 clarity, Brian Gavin Blue round ideal cut diamond with medium blue fluorescence, graded by the American Gem Society Laboratory (AGSL) with an overall cut grade of AGS Ideal-0 on their Proprietary Light Performance grading platform. According to the AGSL, the diamond has a total depth of 61.8% with a table diameter of 55.5% and a crown angle of 34.7 degrees which is offset by a pavilion angle of 40.6 degrees with a thin to medium, faceted girdle and a pointed culet. This is a classic round brilliant cut diamond which is cut to the center of the range specified by the AGSL for their zero ideal cut proportions rating, it has been optimized to produce the highest volume of light return possible. The primary inclusions which the VS-1 clarity grade is based upon are indicated as being diamond crystals and clusters of pinpoint size diamond crystals known as clouds, they are nothing more than tiny diamonds that were trapped within the larger diamond crystal as it formed…

The second option which you expressed an interest in is a 1.247 carat, H-color, VS-2 clarity, Brian Gavin Blue round brilliant ideal cut diamond with strong blue fluorescence, also graded by the AGSL with an overall cut grade of AGS Ideal-0 on the Light Performance grading platform. According to the AGSL, the diamond has a total depth of 61.7% with a table diameter of 57% and a crown angle of 34.9 degrees which is offset by a pavilion angle of 40.9 degrees with a thin to medium, faceted girdle and a pointed culet. Here again, the diamond has been cut to the center range of proportions and is optimized to exhibit the highest volume of light return possible. The primary inclusions are indicated as being twinning wisps, crystals and clouds… twinning wisps are internal twisting of the crystal plane of the diamond.

I compared the ASET Scope and Ideal Scope images for the two diamonds and feel that they are cut to the same level of optical symmetry and that they will both exhibit large flashes of brilliance and dispersion, with a high degree of scintillation. I’m inclined to go with the 1.216 carat, H-color, VS-1 clarity, Brian Gavin Blue diamond with medium blue fluorescence because the proportions are just a little tighter and I prefer diamond crystals to twinning wisps in terms of inclusions… the reality however is that the inclusions within both diamonds are perfectly fine and this is merely a reflection of my personal preference.

Medium vs Strong Blue Fluorescence in H color diamond:

There seems to be lot of misinformation and conflicting statements on the internet pertaining to the effect of blue fluorescence upon a diamond, and this causes a lot of people to be concerned about strong blue fluorescence when there is little need for concern because 98% of gem quality diamonds with blue fluorescence do not exhibit any negative properties as a result of the fluorescence… a fact supported by a study conducted by the Gemological Institute of America (GIA) in 1998 on the effect of fluorescence upon gem quality diamonds.

The general consensus within the gemological community is that faint blue to medium blue fluorescence is little more than an identifying characteristic, which might provide a slight boost in body color since the blue fluorescence will help to filter or offset any slight yellow hues which might be present within the diamond.

The effect of strong blue and very strong blue fluorescence upon the body color of a diamond is more substantial, however in most cases the fluorescence will only have an effect upon the body color of a diamond when it is exposed to strong ultra-violet light, such as direct sunlight which will activate the fluorescent molecules within the diamond.

Strong blue fluorescence in h color diamond, Brian Gavin Blue, AGSL 104052029007

Very strong blue fluorescence has been known to make diamonds look milky or cloudy, but again this is in less than 2% of gem quality diamonds. This is why it is important to work with a vendor like Brian Gavin when purchasing a diamond with blue fluorescence, because his selection criteria for diamonds placed in the Brian Gavin Blue collection, is that the fluorescence can not be affecting the diamond in a negative manner. By the way, the strong blue fluorescence within the 1.216 carat, H-color, VS-1 clarity, Brian Gavin Blue diamond pictured to the left, is only visible like this when the diamond is exposed to black light, in this case it was photographed in a pitch black room.

It is unlikely that there will be a distinct visual difference between an H-color diamond with medium blue fluorescence and an H-color diamond with strong blue fluorescence, when they have both been cut to the same range of super ideal proportions, and a exhibit exceptional optical symmetry. While it is possible that the H-color diamond with strong blue fluorescence might face-up a hint whiter than the H-c0lor diamond with medium blue fluorescence, it is also possible that it might not because the reality is that every color grade is based upon a range of color, and thus it is impossible to accurately determine which diamond will face up whiter due to the presence of fluorescence because we don’t know where in the range of color each diamond sits… suffice to say that the fluorescence will have a slight positive impact upon the body color of the diamond and it is likely that the diamond will face up whiter with fluorescence than it would without it.

For instance, assuming that this 1.234 carat, H-color, VS-2 clarity, Brian Gavin Signature round brilliant ideal cut diamond has an intensity of color which is identical on the scale to that of the 1.216 carat, H-color, VS-1 clarity, Brian Gavin Blue round ideal cut diamond, then technically speaking the 1.216 carat with strong blue fluorescence is likely to face-up just a little whiter because the blue fluorescence will help to filter out some of the yellow hues which may be present within the diamond.

About the Author

Dive deep into the glittering world of diamonds with Todd Gray, the CEO of Gray Matter Development, LLC. Todd has 35+ years of experience as a diamond buyer and trade consultant. He ghostwrites content for several online vendors and is an avid Freediver, currently exploring the Cenotes of Yucatan, Mexico. Dive into brilliance with Todd Gray!