Color Typing

They’re all diamonds, yes, but color does make a difference.

Let’s start this piece by asking what on the surface might seem like a very simple question, Shouldn’t two diamonds of the exact same weight, same clarity, same color, exact same proportions, non-fluorescent, same purchase date, same lab grading report date, both bonded with the exact same mark up cost the same? Well if you ask the labs or check with any of the major price guides like Rapaport, the answer would be a resounding YES.

But pick up your phone, visit your local jeweler, surf the web and I promise you you’ll find twins that are not the same price. In fact, not only are they not the exact same price but in some cases they’re not even close. You’ll even find two identical diamonds at the same location with totally different prices. Why? How can this be? It’s true not all SI-1’s are created equal. Some have centralized inclusions while others have perimeter inclusions which are certainly more desirable and valuable. But what of the VS’s? I can honestly tell you I’ve never met a VS diamond I didn’t like. So where’s the answer?

The answer is in the color. What the industry has been aware of but hasn’t shared with the rest of the world is “Color Typing”. In the spring of 1999 a wonderful gemological color grading device hit the market. What I’m talking about is the Gran Full Spectrum Colorimeter DC2000fs by Gem Instruments. For the first time we can actually prove that not all H’s, G’s or F’s are created equal. This new colorimeter is so precise we can now actually break down each color grade into five color types. For example, instead of asking someone what color a diamond is, we should ask what is the diamond’s color and type. Example: an H can be an H1, H2, H3, H4 or H5 (H1 being the best borderline G and H5 is a borderline I color). When you combine colors and types with grade bumping, two diamonds can have the perception of being the same but be from different parts of the rainbow.

When will the labs start breaking down each color into types? Who knows! I know the price guides won’t be the vanguard until at least one lab steps up to tell us that not all identical diamonds of the same color are created equal. Naturally an F1 should cost more than an F5. But if the labs won’t tell you, how can you determine a diamond’s color and type without their help? Easy, have the store run a colorimeter tape and attach it to the appraisal so you will know if your G is a strong G or a weak one. Make the sale contingent on an independent appraisal agreeing with the colorimeter tape or your money back.

I wish the labs did color typing since the technology is now available. But “Color Typing” is just not profitable for labs. Jewelers are naturally going to send their stones for a lab grading report where they get treated the nicest and are the least critical. That’s why there are five EG or IGI reports out there for every one GIA report. “Color Typing” may never get recognized by the labs but that doesn’t mean jewelers don’t have the access to colorimeters. Knowledge is power. As the buyer you have every right to know a diamond’s color and type. Just ask.

by Fred Cuellar, author of the best-selling book “How to Buy a Diamond.” More questions? Ask the Diamond Guy®

True Weight

Weighing the Facts:

The “True Weight*” of Diamonds

One-carat diamonds offered for sale rarely truly weigh one carat if cut correctly.

Let me explain. Diamonds are a lot like people. They come in all shapes and sizes, and just like people, they can carry a little extra weight. In fact, in the community of diamonds, more diamonds are “overweight” than in the community of people: Up to 88% of all diamonds. The sad part is that it’s the diamond industry that is purposely producing all of these chubby diamonds! In 1919, over 90 years ago, a gentleman by the name of Marcel Tolkowsky determined that the diamond industry as a whole was cutting diamonds incorrectly and adversely affecting the diamond’s sparkle. Mr. Tolkowsky released a paper on the correct way to cut a diamond so it would have maximum sparkle (light return); no excess body fat. The Tolkowsky cut ended up becoming the American ideal. Subsequently, in the 1950’s, a gentleman by the name of R.W. Ditchburn applied the same mathematics in order to trim the fat off the other shapes (marquise, pear, oval, etc.). For decades if you asked for a well cut “Ideal” diamond of a particular size, you got it. Then the marketeers convinced the public that a one carat diamond or more was the dream size. That’s where the problems crept in. Diamond cutters all over the world started inventing their own criteria for “a well proportioned stone” so they could fatten up the diamond. Clearly we have a problem when 75% to 88% of all one carat diamonds are overweight! Just like in the Wendy’s commercial where there was a whole lot of bun and very little meat, we are running into the same problem today with diamonds that should be 1 carat but are cut fat so they will tip the scales over one carat.

Solution: The only way the problem is going to be solved is for the diamond buying public to start asking for the diamond’s “True Weight,” (a diamond in which the crown height plus max girdle thickness plus pavilion depth equals the total depth percentage and whose proportions meet class I or class II criteria.) I’ve never met a jeweler who will volunteer to the consumer that the device used to measure the diamond’s vitals (sarin or megascope machine) also has a fat content measuring button! It’s called the re-cut feature. Once a diamond has been analyzed, all the grader has to do is enter the recorded data into the re-cut program, enter the desired results, (like a plastic surgeon showing you what your nose will look like after the surgery) and click the mouse. In seconds the re-cut program will announce what the diamond should have weighed if it had been cut correctly vs. its current weight. Practically every diamond I see is overweight by 20%-30%!

It is the diamond’s “TRUE WEIGHT” we should be paying for, not extra love handles left on by the cutter. If enough of us demand to only pay for a diamond’s “True Weight” versus its “over-weight” then maybe some day the cutters will get the message.

*If you would like to determine your diamond’s “True Weight,” please call the National Diamond Helpline at
1-800-275-4047 with your diamond’s vitals and we’ll tell you what your diamond should have weighed.

by Fred Cuellar,
author of the best-selling book “How to Buy a Diamond.” More questions?
Ask the Diamond Guy®

Clarity Spotting

Believe it or not, clarity grading a diamond is easier than learning your ABC’s. There are two main categories we want to be concerned with: The diamond with inclusions1 and blemishes2 we can see with our own eyes, category I, and those that appear to be “eye clean,” category II. Once we’ve determined which category a diamond falls in, we can break it down into sub-categories.

Category I: The Imperfects – SI2, I1, I2, I3 (a.k.a., River Rocks, Bluff Diamonds, Commercial Grade and Drill Bit Dodgers) While the easiest way to determine the clarity grade of a diamond is just to ask the seller, this assumes he’s telling you the truth. But since these four grades are the bottom of the barrel, I’m met very few vendors who will brag about how bad their diamonds are. The vendor is also aware that even if you’re farsighted and they could misrepresent these dogs, it’s not very likely your fiancé or independent appraiser will fall into the same trap. Therefore, if a jeweler tells you your diamond is an SI2, I1, I2 or I3; know you’ve gone as low as you can go. These grades tend to be popular with people who want size over quality. In pictures 1, 2, 3, 4, 5, 6, 7, 8 and 9 you can see some great examples of the “bull in the china shop” kind of damage you can expect to find in these moon rocks.

imperfects 1, 2 and 3imperfects 4, 5 and 6imperfects 7, 8 and 9
Category II: “Eye Cleans”

A. The Investments – Flawless, Internally Flawless, VVS1, VVS2 (a.k.a., Bentleys, Rolls, Safe Deposit Rocks)
When you look at pictures 10A, 10B, 10C and 10D, you’d swear you’re looking at the same diamond, but you’re not! You’re looking at four different round diamonds viewed under 10X magnification. Which one is the Flawless, which one is Internally Flawless and which ones are the VVS? If all four grades look identical under magnification to the average bear, or are indistinguishable to gemologists without the aid of a loupe3 or microscope, then don’t worry about it. What makes these rocks distinguishable from the rocks in the first category is their LACK of inclusions, not the presence of any.

Click on any of the images to view an enlarged image.
B. The Street Legals – VS1, VS2 – appropriately named due to being the highest grade recommended to wear or mount into jewelry (a.k.a., Mercedes, The Benz, The Lambs [short for Lamborghini]). This category is my favorite for a variety of reasons; not only are they practically microscope clean and totally “eye clean,” they allow the purchaser to get good to exceptional quality without sacrificing too much on size. In pictures 11A and 11B the diamonds appear flawless, until we zoom in (11C) and easily find pinpoints and small crystals (smaller than a grain of salt) caught in the diamond’s lattice.
Click on any of the images to view an enlarged image.
C. The Slights – SI1 – named because they have slight problems but nothing that will effect the beauty. The SI1’s are easy to grade. They always look great to the eye, but the minute you pick up a loupe even a novice can locate the imperfections. Because all the inclusions are typically larger than a grain of salt but small enough to stay under the “eye clean” radar, SI1’s become a popular choice for maximum size but above average quality. In pictures 12A, 12B 12C and 12D we see classic crystals, feathers, abraded girdles and pinpoints one might expect to see in an SI1.
Click on any of the images to view an enlarged image.
1Inclusions – imperfections inside a diamond (carbon, feather, crystal, pinpoint, cloud)
2 Blemishes – imperfection on the outside of a diamond (chip, scratch, fracture, polishing lines)
3Loupe – a small magnifying glass used to view gemstones.
(All photographs were taken by acclaimed photographer and artist Ricky Fernandez)

by Fred Cuellar, author of the best-selling book “How to Buy a Diamond.” More questions? Ask the Diamond Guy®

Color Grading Scale

Checking your diamond’s report card.

Diamonds come in virtually all colors of the rainbow, from the “beautiful violet” of the Hope diamond to shades of blue, brown, gray, orange, etc. But colored diamonds are very rare and precious. Chances are, all the diamonds you’ll see in your diamond shopping will be white or yellow, and the whiter the better.

The yellow color in diamonds comes from nitrogen, and as a rule, the more yellow the stone, the less value it has. There’s a good reason for this. The yellower the stone, the less sharp and sparkly it appears. A whiter stone lets more light pass through it, making it sparkle and shine.

The exception to the rule is the canary diamond, which is a beautiful bright yellow and very expensive. Some people are more sensitive to the color of diamonds. What may appear slightly yellow to you may look clear to another person, so it will take a higher color grade to satisfy you.

The best way to judge the color of a diamond is to compare it to a master set or a colorimeters. A master set of diamonds has been graded in a laboratory. A colorimeter is a devise that grades the diamond automatically without the need of human eye participation.

Either ask the jeweler for a set and compare the diamonds you’re thinking of buying with the diamonds in the master set or have the jeweler place the diamond in the colorimeter to get an accurate grade.

FRED’S ADVICE: Go for grades H or I. Once mounted, they’ll look just as good to the average person as the higher grades, without costing a bundle. The average diamond purchased in the U.S. is color grade M or N, but the customer is usually told it’s higher.


D, E, F: Colorless

G, H, I: Nearly colorless

J, K, L: Slightly yellow

M, N, O: Light yellow

P, Q, R, S, T, U, V, W, X: Darker yellow

Z: Fancy colors

Even though there are several grades in each category, there are slight differences between the letter grades. D is the clearest and most valuable, X is a dingy yellow and least expensive. Z grade and beyond-colored diamonds-are the rarest and most expensive.



Fluorescence is a diamond’s reaction to ultraviolet (UV) light. Some diamonds glow in different colors under UV light, and the general rule is to avoid them. If you put a diamond under UV light and it glows strong blue, the diamond may look dull in the sunlight. Diamonds with strong fluorescence may be worth up to 20% less than diamonds which do not fluoresce. Faint fluorescence which doesn’t fog the diamond is OK.


Phosphorescence is a type of photoluminescence related to fluorescence. A phosphorescent diamond also reacts to ultraviolet (UV) light, but instead of immediately emitting a glow when ultraviolet light is present, the diamond will absorb some of the radiation from the light and emit it even after the exposure of the UV light is over. Translation: phosphorescent diamonds can look poor (foggy and hazy) outdoors and continue to look poor for hours later even though the diamond is no longer being exposed to harmful UV rays. Metaphorically, we could say a phosphorescent diamond is susceptible to sunburn. Not a good thing.


Corresponding grading means matching clarity grades with color grades. For every clarity grade, there’s a color grade that corresponds, or makes the best match in determining value. Diamonds that have corresponding grading sell for higher prices originally, and they also appreciate in value more than diamonds that don’t, and therefore have higher resale value. Buying a diamond with non-corresponding clarity and color grades is like buying a pink Porsche: it’s okay as long as you don’t try to resell it. The market for pink Porsches just isn’t as good as the market for, say, red Porsches.

Here’s a list of clarity grades and their corresponding color grades. Notice that for each clarity grade there’s a perfect match, and a high and low color that also works well.




D (Perfect) — 10.00%

E (Low)


D (High)

E (Perfect) — 9.25%-9.99%

F (Low)

VS1, VS2:

F (High)

G (Perfect) — 8.50%-9.24%

H (Low)

SI1, SI2:

H (High)

I (Perfect) — 6.50%-8.49%

J (Low)


No corresponding color grades

The value of a stone is always based on the lowest clarity or color grade and its highest corresponding grade. For example: let’s say you purchased a stone with a clarity grade of SI1 and a color grade of G. You can see above that G is not a corresponding color for an SI1 stone. The SI1-G diamond will cost you more than the SI1-H, but will appreciate no more over time than the SI1-H.

When you don’t correspond the grades — say you buy high clarity and low color, or high color and low clarity — you’ll never get your money back for the higher grade. For example, an SI1-F would resell no higher than the value of an SI1-H, and a VS1-I would resell no higher than the value of an SI1-I. A diamond that is not correspondingly-graded could be expected to appreciate 2% to 4% per year.

by Fred Cuellar, author of the best-selling book “How to Buy a Diamond.” More questions? Ask the Diamond Guy®

Clarity Grading Scale

The clarity of a diamond depends on how “clear” or “clean” it is — how free it is of blemishes and inclusions when viewed with the naked eye and with a 10X loupe or magnifier. Let’s define our terms.

BLEMISHES: Imperfections on the outside of a diamond

Chip: A little piece missing, caused by wear or the cutting process.

Scratch: A line or abrasion.

Fracture: A crack on the diamond’s surface.

Polishing lines: Fine lines on the stone’s surface formed during the polishing stage.

Natural: An unpolished part of the diamond.

Extra facets: Additional polished surfaces that shouldn’t be there and spoil the symmetry of a diamond.

Bearding: Very small fractures on an edge of the diamond.

INCLUSIONS: Imperfections inside a diamond.

Carbon: Black spots inside a stone.

Feather: Internal cracking.

Crystal: White spots inside a stone.

Pinpoint: Tiny spots, smaller than a crystal.

Cloud: A group of pinpoints, which may give the impression of a single large inclusion.

Loupe: (pronounced loop) a small magnifying glass used to view gemstones. Any good jeweler will let you use one, and show you how. They should be 10X, or 10-power magnification, and the housing around the lens should be black so as not to distort the color of the stone. The Federal Trade Commission requires diamond grading to be done with a 10X magnifier, and any flaw that can’t be seen under 10X magnification is considered nonexistent.

Here are the CLARITY GRADES OF DIAMONDS, as established by the Gemological Institute of America (GIA), and their corresponding definitions using hard-grading standards:

FLAWLESS: Free from inclusions and blemishes when viewed under 10X magnification. Very rare and very expensive.

INTERNALLY FLAWLESS: Free from inclusions; may have slight blemishes when viewed under 10X magnification. Also very rare and very expensive.

VVS1 AND VVS2 (VERY, VERY SLIGHTLY INCLUDED): Has minute inclusions or blemishes the size of a pinpoint when viewed under 10X magnification. Rare and expensive.

VS1 AND VS2 (VERY SLIGHTLY INCLUDED): Has inclusions or blemishes smaller than a grain of salt when viewed under 10X magnification. No carbon, fractures or breaks. High quality.

SI1 (SLIGHTLY INCLUDED): Has inclusions or blemishes larger than a grain of salt when viewed under 10X magnification, and these inclusions can be carbon or fractures. Almost all SI1 diamonds are eye-clean, which means the flaws can’t be seen with the naked eye. Good quality.

SI2 (SLIGHTLY INCLUDED): Has inclusions or blemishes larger than a grain of salt when viewed under 10X magnification, and some of these flaws may be visible to the naked eye. Borderline diamond.

I1 (IMPERFECT): Has inclusions and blemishes visible to the naked eye. Commercial grade. Not my taste!

I2 (IMPERFECT): Has inclusions and blemishes visible to the naked eye that can make as much as one-fourth of the diamond appear cloudy and lifeless. Same as above.

I3 (IMPERFECT): Has many, many inclusions and blemishes visible to the naked eye. Not a pretty diamond. Very little luster or sparkle. Bottom of the barrel.

FRED’S ADVICE: Aim for an VS2 diamond. Many people unwittingly buy SI1 and SI2 stones, but if you shop carefully you can buy an VS2 stone for the same price that most SI2 stones are sold for.

by Fred Cuellar, author of the best-selling book “How to Buy a Diamond.” More questions? Ask the Diamond Guy®

Carat Weight

When you ask someone what they want in a diamond, usually the first thing they’ll say is big. So let’s talk first about carat weight.

What is a carat? We already know it’s a measure of weight, not size, but it’s also a word with a fascinating history. Carat is derived from carob, the bean that’s often used as a chocolate substitute.

Carob trees grow in the Mediterranean region, and in ancient times a diamond of one carat, or carob, was equal in weight to a single bean, or seed, of the carob tree. In the Far East, rice was used — four grains equaled one carob bean.

Eventually the carat was standardized at 200 milligrams (1/5 of a gram), and the grain was standardized at 50 milligrams. Sometimes you will hear a diamond dealer refer to a one-carat diamond as a four-grainer. Diamond weights are also referred to in points. One carat equals 100 points, so a 75-point diamond would weigh 3/4 of one carat. (It’s not a diamond with 75 points on it, as some people think!)


You’ve no doubt heard or seen the marketing slogans, “A diamond is forever;” “Say you’d marry her all over again with a diamond anniversary ring;” and “A one carat diamond is one in a million.” These all come from ad campaigns by DeBeers, the world’s largest diamond conglomerate. Through their clever marketing they have established the one-carat diamond as the minimum size to buy. That’s one reason for the substantial price jump when a diamond reaches one carat. Another reason is that a good one-carat diamond is one in a million. But don’t be swayed by advertising. There’s no magic in size, and the average diamond purchased in the U.S. is 38 points — just over 1/3 of a carat.

by Fred Cuellar, author of the best-selling book “How to Buy a Diamond.” More questions? Ask the Diamond Guy®.

BACK to Diamond Articles Index.

How to Buy a Diamond: The 4 C’s

And guys, we’re not talking Corvettes, Cigars, CDs and Courvoisier

Somewhere along the line it happened: Your honey went from being your honey to being THE honey of all honeys. A ring starts to weigh on your mind. But before you toss out all your little black books and get down on bended knee, you have to get a *ring*. Creative types might think they can get away with the ring from the Cracker Jack box, but we can’t guarantee an enthusiastic “yes” from your desired spouse-to-be. Most likely, she’ll be looking for something brilliant and white (but not necessarily, keep reading to the end) — a diamond.

Blame it on the Archduke Maximilian of Austria, who started the diamond engagement ring trend way back in 1477 when he presented one to his beloved, Mary of Burgundy. Ever since then, men have been saving up to buy one. Although we’re sure there are a few savvy women out there saving up for a man’s engagement ring, or even thrifty brides-to-be who are chipping in for their own! Anyway, although two month’s salary is a good guideline to use in determining how much to spend, it’s a very personal choice and, after all, love tends to blur one’s guidelines a bit anyway.

There are seven basic shapes to consider when diamond shopping: oval, round, marquise, emerald, pear-shaped, and heart-shaped. Most important, however, is the quality of the stone, and to determine quality you must understand the 4 C’s, which are as follows.

Carat weight: The weight/size of a diamond is measured in carats. One carat is divided into one hundred segments called “points.” As in the decimal system, one hundred and twenty five points equals one and a quarter carats.

Clarity: This is the degree to which a diamond is free of inclusions. Where the inclusions lie, their size, and their type determine the value of the stone. Inclusions are rated as follows:

FL = Flawless

IF = Internally Flawless — minor surface blemishes

VVS1-VVS2 = Very, Very Small inclusions

VS1-VS2 = Very Small Inclusions

SI1-SI2 = Small Inclusions

I1-I2-I3 = Imperfect — inclusions visible to the eye

Slight inclusions, although they reduce the value of a diamond, do not take anything away from its beauty.

Color: This is another aspect where scarcity determines value. Colorless diamonds are extremely scarce in nature. Gradations from high white to beginning yellows are not easily perceptible to an unpracticed eye. The exceptions to high value equaling colorless stones lie in the bright-colored diamonds, i.e., amber, red, blue, etc.These diamonds, in the larger sizes, command enormous prices and are quickly snatched up by collectors worldwide.

Cut: Today the art of diamond cutting has been refined to precise mathematical formulae. Most diamonds are cut with 58 facets. A good cut is determined by the stone’s light-reflecting properties and its light dispersion. The cut you finally choose, however, is a matter of personal taste.

Your sweetie’s not the diamond type? Why not consider a different gemstone? Although colored gemstone engagement and wedding rings are unusual in the U.S. today, they are the traditional choice for wedding and engagement jewelry for the royal families of Europe:

Princess Diana and Sarah Ferguson both received colored gemstone engagement rings. Rubies, sapphires, and emeralds have been treasured for thousands of years, longer than any other gemstones. This venerable tradition has been revived and is now the strongest new trend in bridal jewelry. A growing number of famous women today — including Ivana Trump, Kirstie Alley, and Jane Fonda — are wearing engagement rings featuring colored gemstones instead of diamonds. Sapphire is the most popular choice for a colored gemstone engagement ring, followed by ruby and emerald.

Gemstones also have specific meanings (besides your eternal love for her, of course):

Sincerity: Sapphire A gift of this gem says you’re not just kidding around.

Electricity: Tourmaline Squeeze this gem and it gives off electricity. Give it and create sparks.

Passion: Ruby The ancients believed this gem contained an unquenchable fire.

Marital Harmony: Aquamarine Say you’re sorry, give her this gem and promise that it will never, ever, happen again.

Fertility: Emerald This gemstone may not help create quintuplets, but twins aren’t out of the question.

Love: Emerald The gem of Venus says love lot more persuasively than a dozen roses.

Hope: Opal Show your faith that things will work out. Now all you have to do is figure out her ring size…

by Fred Cuellar, author of the best-selling book “How to Buy a Diamond.” More questions? Ask the Diamond Guy®

BACK to Diamond Articles Index.

How Much Is A 1Ct VS1, G?

This may seem like a reasonably easy question for someone in the jewelry industry to answer but it’s actually quite difficult if the quote is to be accurate. In fact, an accurate answer cannot be derived due to lack of information. Probability comes into play when we don’t have the information needed to make an informed decision. When we don’t have enough data, all we are left with are “reasonable guesses.” Here are just some of the things we don’t know: For starters, what type of 1ct are we talking about; a shy, full, heavy or true? What type of VS1 are we talking about; a hard, lab, bonded, paperless, partial or split? What type of G; G1, G2, G3, G4 or G5? How well proportioned is it; Class I, Class II, Class III, Class IV, Ideal, Signature, Hearts and Arrows, Eight Star, High Definition or Kaplan? (If they use one of these titles to advertise the diamond is well-proportioned, what are the specifics in angles, percentages and ratios of that brand?) Once you know the specifics (proportions), do they give you enough measurements to determine if the crown angles and pavilion angles are universal or if the diamond is warped? Please don’t forget about fluorescence. Is the diamond fluorescent? If it is, is it strong, medium or faint fluorescence? Was the diamond annealed, fracture filled, bleached, assembled or laser drilled? What equipment was used to measure the diamond? Was the equipment calibrated before it was used? Does the paperwork that comes with the diamond really match the stone? Where did the diamond come from? Is it a blood diamond? Is it a secondary market diamond? Finally, once you ask every last detail, how can you know what you’ve been told is factual?

Time for a joke. There are three men on a train–an economist, a logician and a mathematician. They have just crossed the border into Scotland and they see a brown cow standing in a field. The cow is standing parallel to the train.

The economist says, “Look. The cows in Scotland are brown.”

The logician says, “No. There are cows in Scotland, of which one at least is brown.”

The mathematician says, “No. There is at least one cow in Scotland, of which one side appears to be brown.”

How much is a 1ct, VS1, G? If you were to ask the economist, he might give you more than one answer. If you were to ask the logician, he would be smart enough to ask what type of 1ct, VS1, G you were talking about. And finally, if you were to ask the mathematician, he would say, “Did you forget about one thing? How much profit does the seller want to make?

by Fred Cuellar, author of the best-selling book “How to Buy a Diamond.” More questions? Ask the Diamond Guy®