Diamond Carat Weight

Commonly thought to refer to the actual size of a diamond, a carat is actually a standard unit of measure that defines the weight of a diamond. One carat is equivalent to 200 milligrams. Carat sizes are also expressed as “points”, with a one carat diamond equaling 100 points, a one-half carat diamond being 50 points, a three-quarter carat diamond being 75 points, and so on.diamond_size

Larger diamonds are much more rare than smaller ones. In fact. hundreds of tons of rock and ore must be processed to uncover a single one-carat gem quality diamond, and less than one percent of all women will ever own a one- carat or larger diamond.

Since a carat is a unit of measure and not size, two diamonds of the same carat weight may appear to be different sizes depending on how the diamond is cut. Some diamonds will have extra weight on the bottom part — or pavilion — of the stone, and therefore appear smaller. A premium cut Canadian diamond is perfectly cut, and will appear larger than many diamonds of a heavier carat weight.

Diamond Color

Although most people believe diamonds to be clear or colorless, the majority of diamonds are yellow, brown, and black. Most of those diamonds find their way into industrial purposes, (drill bits, saw blades, etc.) The rarest of all diamond colors are white (or colorless).

As prices of diamonds rise, the shift to diamonds with some body color increases. It is very common to find slightly brown (called “Top Light Browns”) or yellow diamonds in today’s jewelry. The whiter the diamond is, the more valuable the stone is.

Diamonds are graded for color face down, against a white background. Graders are looking at the actual body tone (hue) of the stone and comparing it to a set of master stones graded by the Gemological Institute of America. The diamond is then assigned a letter grade as seen on the accompanying chart. Most diamonds used for jewelry purposes fall into the Near Colorless Category – G to J


The Gemological Institute of America (G.I.A.) grades color alphabetically from D (totally colorless) to Z (yellow).For a diamond to be considered “colorless,” the G.I.A. requires that it be a D, E, or F.  However, the D-Z scale is continuous, so the difference between an F and G is very small.  The average color for engagement diamonds in the retails industry is G to H.

Diamond Clarity

A diamond’s clarity refers to the presence of identifying characteristics on and within the diamond. While most of these clarity characteristics are inherent qualities of the rough diamond and have been present since the earliest stages of the diamond crystal’s growth below ground, a few clarity flaws are actually a result of the harsh stress that a diamond undergoes during the cutting process itself.

If you think about the incredible amount of pressure it takes to create a diamond, it’s no surprise that many diamonds have clarity inclusions — scratches, blemishes, air bubbles or non-diamond mineral material — on their surface or inside. Diamonds with no or few inclusions and blemishes are more highly valued than those with less clarity, not just because they are more pleasing to the eye, but also because they are very rare.

Diamonds are graded for clarity under 10x loupe magnification. Clarity grades range from Internally Flawless, diamonds which are completely free of blemishes and inclusions even under 10x magnification, to Imperfect 3, diamonds which possess large, heavy blemishes and inclusions that are visible to the naked eye.

FL:  Completely flawless

IF:  Internally flawless; only external flaws are present, which can be removed by further polishing the stone

VVS1 – VVS2:  Only an expert can detect flaws with a 10X microscope.  By definition, if an expert can see a flaw from the top of the diamond, it is a VVS2.  Otherwise, if an expert can only detect flaws when viewing the bottom of the stone, then it is a VVS1

VS1 – VS2:  You can see flaws with a 10X microscope, but it takes a long time (more than about 10 seconds)

SI1 – SI2:  You can see flaws with a 10X microscope

I1 – I3:  You can see flaws with the naked eye.  Consider avoiding I2-I3 diamonds.clarity


REMEMBER: For grades IF through SI, a diamond’s clarity grade has an impact on the diamond’s value, not on the unmagnified diamond’s appearance.

While Flawless diamonds are the rarest, a diamond does not have to be flawless to be stunning. Diamonds with VVS and VS grades are excellent choices for both value and appearance. More affordable (and still a great choice) are those diamonds which gemologists call “eye-clean” – diamonds with no inclusions visible to the naked eye. These diamonds are SI1 and SI2 and unless the recipient carries a 10X loupe (a strong jewelry magnifying glass), she won’t see the inclusions.Canada Diamonds recommends diamonds with clarity grades of VS2 and higher to ensure a eye clean diamond.

There are many different types of flaws.  The best way to become acquainted with them is to look at lots of diamonds.  The more common ones are as follows:

Pinpoint:  A very small white dot on the surface of the stone.  By far, the most common flaw

Carbons:  A very small black dot on the surface of the stone.  Less common than pinpoints

Feathers:  Small cracks within the stone, similar in look to broken glass.  Small internal feathers are harmless (other than lowering the clarity rating of the diamond), but large feathers can become a problem because the crack can grow as the diamond ages

Clouds:  Hazy areas within the diamond, actually made up of many small crystals that are impossible to see individually

Crystal Growth:  A small crystalline growth within the diamond.  Looks like a small diamond within the big diamond

Many people make clarity the least “important” of the 4 Cs when purchasing their diamonds.  The rationale is obvious — when your partner shows the ring to all her friends, the likelihood that one of them will pull out a 10X microscope to examine the flaws on her diamond are very slim.  Given that, why spend a lot of money on a VVS1 diamond when an SI2 will look exactly the same to the naked eye?

If you’re purchasing an emerald cut (or any other step cut), consider purchasing a diamond with clarity greater than SI1.  Clarity flaws are much more readily visible in step cuts than in brilliant cuts.

Diamond Cut

First, don’t confuse diamond “cut” with “shape.” Shape refers to the general outward appearance of the diamond, (such as round, emerald, or pear). When a diamond jeweler (or a diamond certificate) says “cut,” that’s a reference to the diamond’s reflective qualities, not the shape (or at least it should be, we have found that even some “jewelers” don’t appear to know the difference between “cut” and “shape”).

Diamond cut is perhaps the most important of the four Cs, so it is important to understand how this quality affects the properties and values of a diamond. A good cut gives a diamond its brilliance, which is that brightness that seems to come from the very heart of a diamond. The angles and finish of any diamond are what determine its ability to handle light, which leads to fire,brilliance & scintillation


When a diamond is well-cut, light enters through the table and travels to the pavilion where it reflects from one side to the other before reflecting back out of the diamond through the table and to the observer’s eye. This light is the brilliance we mentioned, and it’s this flashing, fiery effect that makes diamonds so mesmerising.



It’s easy to see that the deep-cut diamond shown above will have a higher carat weight, but is clearly the less desirable stone!  Many jewelers will not discuss cut proportions unless the customer specifically asks; a stone rich in carat weight but poorly proportioned can be deeply “discounted,” giving the buyer a false impression of a great deal.

In a poorly cut diamond, the light that enters through the table reaches the facets and then ‘leaks’ out from the sides or bottom of the diamond rather than reflecting back to the eye. Less light reflected back to the eye means less brilliance.



Gemologists agree that the best cut diamonds are those that follow a set of formulae calculated to maximize brilliance. These formulae can be seen in a diamond’s proportions, most importantly how the depth compares to the diameter, and how the diameter of the table compares to the diameter of the diamond.

However, the variance in the proportions between an Ideal Cut and a Poor Cut can be difficult to discern by the casual observer.

Because cut is so important, several grading methods have been developed to help consumers determine the cut of a particular diamond. In general, these grades are:

Very Good
Fair & Poor

Selecting the grade of cut is really a matter of preference. To make the best selection, you need to understand the various grades. Please note that the descriptions below are general guidelines.


Ideal Cut 

This cut is intended to maximize brilliance, and the typically smaller table sizes of these diamonds have the added benefit of creating a great deal of dispersion or ‘fire’ as well. Ideal quality diamonds are truly for the person who enjoys knowing that he has one of the finest things that money can buy. This category applies only to round diamonds.


In the case of round diamonds, many Premium Cut diamonds have cuts that are the equal of any Ideal Cut diamond, though they often can be purchased at slightly lower prices than AGS Ideal Cuts. They are intended to provide maximum brilliance and fire. Like the Ideal Cut, these are also for the person who enjoys knowing that he has one of the finest things that money can buy.


Very Good 

These diamonds reflect most of the light that enters them, creating a good deal of brilliance. With these diamonds, the cutters have chosen to stray slightly from the preferred diamond proportions in order to create a larger diamond. The result is that these diamonds fall slightly outside of some customers’ preferences in terms of, for example, table size or girdle width, though, in many cases many of the parameters of diamonds in this range will overlap with certain parameters of diamonds in the Ideal or Premium ranges. Generally, the price of these diamonds in slightly below that of Premium cuts.



Diamonds that reflect much of the light that enters them. Their proportions fall outside of the preferred range because the cutter has chosen to create the largest possible diamond from the original rough crystal, rather than cutting extra weight off to create a smaller Premium quality diamond. Diamonds in this range offer an excellent cost-savings to customers who want to stay in a budget without sacrificing quality or beauty.


Fair & Poor 

A diamond graded as fair or poor reflects only a small proportion of the light that enters it. Typically these diamonds have been cut to maximize the carat weight over most other considerations. Most of these type of cut diamonds can be found in retail mall jewellery stores.