CUT

We've already considered most of the essential facts about the cut. However, your may confuse the quality and precision of the cut with it's shape-Oval, Marquis, ect. Bear this in mind in order to clarify this point if necessary.

There are many shapes and sizes of diamonds. But whatever the shape or size, the cut is the technical quality which can vary, and which is unique to each stone. The cut is the most important, only a skilled diamond cutter can unlock the hidden beauty fire and brilliance. As they say in the trade "The magic is in the make".

The better the quality of the cut, the better the stone will create BRILLIANCE and FIRE and helps determine the value of each stone.

  When a diamond is cut to good proportions, light is internally reflected from one facet to another and then dispersed through the crown, or top of the diamond (1). If the cut is to deep, then some light will escape through the opposite side of the pavilion, or bottom of the diamond (2). If the cut is to shallow, then some light will escape through the pavilion, or bottom, before it can be reflected (3).

  If you place two diamonds of similar carat weight, clarity and color side by side and find one to be less fiery than the other, the fault lies in the cutting. the cutter has opted to create a larger diamond at the expense of its brilliance. The larger stone would appear to give you more diamond for your money, when in fact its value has been diminished.
  Over the centuries diamond cutters have experimented with many angles of cut in order to capture the maximum brilliance of the reflected light (usually comes with a premium price). When a stone has been cut to deeply it looks dark and if cut too shallow the girdle reflects back to the surface creating a watery or fish eye look also both should be (usually lower priced). When you shop be aware, don't just compare prices compare the diamonds measurements!

The diagram on the right provides some visual explanation three images of actual round diamond's finish-grade and proportions. Any deviations in symmetry and intersections of facets, both of which influence the degree of brilliance of a diamond. I'll try not to confuse you with technical details, yet I feel this is a very important factor. The proportions of the stone, vital to the diamond's brilliance and fire, influence its luster, and therefore any significant deviation from the ideal may cause the stone to appear dull and undesirable. An appreciation of the proportions and measurements is posted for round brilliants. The proportions are measured and posted for fancy shapes but no final analysis is made as there no universally accepted standard proportions for these in existence.
  

Round

The round brilliant is the most popular of all the polished diamond shapes. Designed to provide maximum optics for brilliance and scintillation.

Oval

The oval has an elliptical shape when viewed from the top and is an adaption of the round brilliant and appears larger than a round stone of the same carat weight. A shallow cut oval will produce a dark area in the center known as the bow tie effect. Keep in mind this is a characteristic of oval shapes and most fancy cuts. It is also one of the less common fancy shapes, yet very unique and economically priced.

Marquis

The marquise is the name given to the diamond shape that is long and pointed at both ends. Looks something like a football when viewed from the top. Some people prefer a long and narrow cut while others prefer a shape that's short and fat. A characteristic of this fancy shape is the dark center known as the bow tie effect. Depending on It's depth, the real shallow ones will show a more pronounced bow tie, a deep one will show less.

Heart

The heart shape is perhaps the most romantic of what are known as the fancy shapes. Look for a good cut and color and definitely not deep if you want something different this is the one.

Pear

The pear shape is the English name for the French " pendeloque" which is related to our word pendant. A popular cut looks like a tear drop. This is a traditional cut which is perfect for pendants, drop earrings and many applications.

Emerald

The emerald cut is rectangular, with facets on each of the sides and across the corners. These can be beautiful stones. With stepped facets the sheen tends to be large flashs of these stepped angles on the pavilion of the stone. With this cut I feel that color and clarity plays a very important role in the beauty of the stone so stay above "VS,2" clarity and " G" color or better for a super look.

Trillium

The Triangle or Trillion cut straight or cushioned sides a modern shape is one of my personal favorites with three equal sides and plenty of dazzle. Well suited for center or shoulder setting and as always avoid deeper or shallower cuts.

Princess

The princess is a modern fancy shape and is becoming one of the most popular. Generally slightly off from a perfect square, yet if well cut equals or surpasses the fire and brilliance of a round shape. One of it's characteristics is slightly deeper than rounds or other fancies.

With the many various shapes, and a good working knowledge of how diamonds are graded you can use your eyes to measure the overall effects of these cuts and pick the one that's just right for you...

COLOR

Most diamonds look colorless, but there are many subtle shade differences and the closer a diamond it to having no color the more valuable it becomes. In my opinion, color is the second most important to cut, simply because it's visible to the naked eye.
Why does color vary? Well, in the chaos of extreme temperature and pressure that first created diamonds, traces of other elements became mixed with the pure carbon which is hardly surprising.
It is these traces that give a diamond its color-or lack of it. Diamonds with no traces of color at all are very rare.

But also rare are diamonds with a strong pure color. These are called Fancies and are extremely rare. Pink and blue are the most prized, but virtually any color is possible.

Most gem quality diamonds, seen on their own, do in fact appear to be colorless. But usually they do have at least a hint of color-this is normally yellow, due to traces of nitrogen.

The only real way of determining the exact color of a diamond is to place it next to another diamond which has previously been color graded.

International standards have been established for grading diamonds according to extremely subtle differences in color. One the main scales is the G.I.A. (Gemological Institute of America) shown below.
   

CLARITY

Nature being what it is, diamonds may show peculiarities of crystallization, which could be minute traces of other minerals trapped during the crystallization process. These may show up as tiny black or white marks.

These natural characteristics are called "inclusions" - nature's fingerprints.

The number, size and position of any inclusions determines the CLARITY of a diamond. The fewer the inclusions the rarer it will be, and the more light it will reflect, making it more valuable. Since it's very rare to find a diamond that's flawless, the closer to flawless the greater the value.

As with COLOR, there are internationally agreed and accepted standards of CLARITY.

The major categories from the G.I.A. systems of clarity grading are shown below.

THE F.L. GRADE (Flawless)
The term F.L. or flawless is used for diamonds in which a qualified observer, under favorable lighting conditions, cannot find internal characteristics and/or faults by thorough examination with a 10X corrected loupe.

THE I.F. GRADE (Internally flawless)
A diamond which has no internal characteristics but which, due to minor finish faults is not flawless and therefore cannot be designated F.L. or flawless, may be called I.F. or internal flawless provided the finish faults are so minute that they can be removed by a gentle polishing with only an insignificant loss of weight.

THE V.V.S. GRADE (Very, very small inclusions)
The term V.V.S. is used for diamonds with internal characteristics very, very difficult for a qualified observer to find under observation conditions as described. Further, there may only occur insignificant finish faults.

THE V.S. GRADES (Very small inclusions)
The term V.S. is used for diamonds in which it is difficult for a qualified observer, under observation conditions as described, to find either a few somewhat larger internal characteristics or several very small ones.

THE S.I. GRADES (Small inclusions)
The term S.I. is used for diamonds in which a qualified observer may, without difficulty, under observation conditions as described, but, still only by a 10X magnification - find internal characteristics. Further, there may only occur single finish faults of an insignificant kind.

THE I. GRADES (Pique)
The term I or Pique is used for diamonds in which a qualified observer with the naked eye can see internal characteristics and/or in which such major faults occur, which substantially reduce the value of the stone.

CARAT WEIGHT

The last of the 4C's is Carat Weight. A diamond's weight is the simplest of its characteristics to measure, and from the earliest times it was used to calculate the value of a diamond.

The carat is a unit of weight which derives from the carob seed. The pods of the carob, or locust, tree contain tiny seeds which are remarkably consistent in weight. These seeds were used by early gem traders to weigh their diamonds.

A 1 carat diamond used to equal the weight of a carob seed, but in today's terms the carat is a standard metric weight of 0.2 grams, and each carat is divided into 100 points.

So for example, a quarter of a carat is 25 points, written as 0.25; a half a carat is 50 points, written as 0.50, and so on.

It is easy to weigh an un mounted diamond, but once it is in a setting it is only possible to estimate its weight by using special gauges and formula.

Remember, Carat Weight has no bearing on a diamond's cut, color or clarity.

 

Diameters And Corresponding Weights Of Round, Well-Proportioned, Brilliant Cut Diamonds