Fancy a little color in that diamond?

Today's blog entry will be on the subject of colored diamonds. 

First I'll run through the definitions: 

Fancy color diamonds: Diamonds which have a vivid or intense color. The hue of these diamonds can vary across the entire spectrum of colors. 

 Each colored diamond will vary in intensity and will therefore be given a classification in regards to how intense the coloring is. It will be classified under one of the following nine saturation grades: 

• Faint, 
• Very Light, 
• Light, 
• Fancy Light, 
• Fancy, 
• Fancy Intense, 
• Fancy Vivid, 
• Fancy Deep, 
• and Fancy Dark. 

The graphic below shows GIA's Fancy Color Grade interrelationships.

(see leibish.com for examples of different grades of colored diamonds)  Fancy Vivid is the grade given to diamonds with the highest level of saturation as can be seen in the chart. 

This is highly desirable, and naturally exceptionally rare.

Something else I wanted to mention is that faintly colored diamonds, or should I say, sub-faintly colored diamonds, which have less color than those with an official designation of "Faint"are unsurprisingly rather common. 

It's the colorless and the intense colors that are rare and hence their cost. Colorless diamonds are assigned the letter "D" when their color is graded by a GIA lab. A diamond with a very slight increase in color (when compared to a D) be assigned an "E", followed by an "F", then a "G" etc, all the way down to Z. Very few people seem interested in diamonds that fall between "K" and "Z". 

Fancy colored diamonds have just a bit more color than a "Z". 

X-Y-Z stones that have yellow or brown as their color do have enough color to be counted as fancy color diamonds.

Each group of gemological labs has its own grading system, but the dominating grading system is the one developed by the Gemological Institute of America (GIA).

Yellow is the most popular fancy color. It appears to have become more and more popular and a number of celebrated public figures have been seen sporting yellow diamond rings. Here are some of the people seen wearing yellow diamonds in recent years: Heidi Klum, Jennifer Lopez, Jessica Alba, Megan Fox, Kelly Clarkson, Anna Kournikova, Carrie Underwood.

Yellow diamonds stand out because they do get noticed, and they are known to be rare. About 10,000 times as rare as white diamonds.

Yellow diamonds are much rarer than white. The yellow color in diamonds is caused by nitrogen replacing carbon atoms in the diamond's molecular structure. Higher levels of nitrogen in the stone's composition results in a deeper color.

Since vividly colored diamonds are indeed rare, you will find that cutters try their best to retain as much of the diamond as possible. Another priority will be on shaping the diamond in such a way as to retain the intensity of the diamond's color. If a colored diamond has not been cut to be perfectly symmetrical it will usually be because this was a necessary compromise to retain more size rather than lop off a few more corners to get it into perfect symmetry. If you prefer your diamond to be perfectly symmetrical, keep looking. You can find them.

Help! I think my girlfriend wants a Marquise Diamond

Question: Hi, Diamond Buying Advice,

I've been looking to get an engagement ring, but am not really sure about all the different diamonds. I have it on good authority that my girlfriend likes the Marquise diamond. Where can I buy the Marquise? Is it expensive?

R.R.

Answer: Hello RR,

The marquise shape of diamond is a very elegant shape. It is often chosen to be worn by women with slender fingers. This shape falls under the category of "fancy cut". 

The length to width ratio is quite important when looking at marquise cut diamonds. I always recommend buying a diamond with an "Excellent" cut. The key to getting a marquise diamond which is brilliant and real sparkly is to check that the following are true of the diamond.

It should have a

Color "I" or lighter

Length to width ratio of 1.80 : 1.00.

As well as a depth of 61%.

One or two percentage points variation on the depth will make almost no difference. But these proportions mentioned above will give you the most brilliance.

The number for the depth percentage is found on a diamond's grading report as well as within the search parameters on a diamond vendor's website.

The length to width ratio is not written on a grading report.

This is the way you calculate it.

Let's say you look at a marquise diamond's grading report which says:

Measurements: 10.25 x 5.75 x 3.47 mm

Press the calculator button on your keyboard (if there is one)

Type in: 

10.75 
/
5.75

= 1.782608695652174

This gives is the length to width ratio.

1.78 : 1.00

This very close to the ideal proportions, but we can look further as it's possible to find one that has proportions even closer to 1.80 : 1.00. 

Here is another one: 10.38 x 5.66 x 3.49 mm

This one gives us a length to width ratio of 

1.83 : 1.00

This one we see ends up being slightly over our ideal, so we continue our search. the next one we decide to check out is a slightly smaller stone with the measurements of 9.69 x 4.70 x 2.76 mm

We do the math: 

9.69 
/
4.70

We find that this one is actually no closer to our ideal as it has a length to width ratio of

2.06 : 1.00

It looks like the first diamond of the three we looked at was the best choice and we might go with that one.

As far as price goes, marquise diamonds are often priced considerably lower than round brilliant diamonds with the same specifications. See these two diamonds compared. The one that is slightly larger is the marquise, and yet it is considerably less expensive than the round diamond. Not everything is exactly the same, however they are both quite close to being near the top of the range with identical color and clarity. 

CARAT	COLOR	CLARITY	CUT	DEPTH	TABLE	POLISH	SYM.	SHAPE	PRICE
0.95	I	VVS2	IDEAL	62.2%	58	EX	EX	ROUND	$6,301
0.98	I	VVS2	PREM	65.4%	63	VG	GD	MARQUISE	$3,719

See these recommended diamond vendors websites for up to date prices.

What is the name of a square diamond?

Question: Hi Diamond Buying Advice,

I was wondering what you call the diamond that has a square shape? Is this a good choice for an engagement ring?

J.R.

Answer: Hi J.R, 

The shape you are talking about must be the Princess cut diamond. It is the second most popular choice for engagement rings. It does have a pretty name. This shape falls in the category of Fancy Cut, which is any shape that is not a Round Brilliant. If you get this kind of shape and want it to look very clear and sparkly choose anything with a letter designation of D, E, F, G, H or I color. The diamond labelled an "I" color would be the most affordable. I recommend to look for a diamond which also has a cut rating of "Excellent".

A diamond with a cut rating of "Excellent Cut" will make a bigger difference than choosing one with a higher color grade.

Say you have the choice of two Princess cut diamonds.

1. One is an "I" color, with an "Excellent" cut.
2. The other is a "G" color with a "Good" cut.

You'll be much happier with the one that has an Excellent cut even though it has a slightly lower color grade of "I".

Fancy Cut diamonds which, as mentioned above, are any diamonds cut into a shape other than Round Brilliant. Fancy Cut diamonds do not have a section on their grading report which mentions the Cut Grade. Fortunately most vendors mention if the cut is Good, Very Good, Premium, Ideal/Excellent.

Diamond Grading Reports issued by GIA, AGSL, or EGL are considered trustworthy descriptions. These labs give you a decent and accurate description of the diamond, though they don't all have the exact same parameters. It's good when you can view the grading report when buying a diamond online.

Here you can see which diamond vendors let you see each diamond's grading report on their website.

Some sites call the Grading Report a Diamond Certificate, though the diamond grading labs actually call them Grading Reports as well as Diamond Dossiers for stones smaller than 1 ct.