- 1. Introduction
- 2. The Four C's
- 3. Cut
- 4. Cut Specifications
- 5. Color
- 6. Clarity
- 7. Carat Weight
- 8. Shape
Beautiful and rare, diamonds are desired for their sparkle and message of love. When you buy a diamond there are four points that you should consider, collectively known as the Four C’s.
Refers to the symmetry and proportions of the stone; it is what gives the diamond its sparkle. There are many diamond shapes to choose from. Whatever shape and quality you prefer, a Laboratory Report should be a requirement for your engagement ring or any significant diamond purchase.
The most desirable diamonds are colourless. The best colour is D, which is almost clear white; the colour scale descends from there through the alphabet toward Z, moving further away from colourless toward yellow or brown tints.
Diamonds have small imperfections in them known as inclusions; the fewer inclusions, the more valuable the stone.
This is the size of the stone. The word carat comes from the carob seeds that were used to balance scales in ancient times.
The cut of a diamond refers to its proportions. Of the 4C's, the cut is the aspect most directly influenced by man. The other three are dictated by nature. Quite often the cut of a diamond is confused with its shape. Diamonds are cut into various shapes depending upon the original form of the uncut diamond, which is referred to as “rough.” Whatever the shape, a well-cut diamond is better able to reflect light.
A diamond's ability to reflect light determines its display of fire and brilliance. Diamonds are usually cut with 58 facets, or separate flat surfaces. These facets follow a mathematical formula and are placed at precise angles in relation to each other. This relationship is designed to maximize the amount of light reflected through the diamond and to increase its beauty.
1. Well Cut
When a diamond is cut to proper proportions, light is reflected from one facet to another and then dispersed through the top of the stone. Within the Well Cut standards are the sub categories of Ideal, Excellent, and Very Good.
Ideal - This range is very strict and combines the best in brilliance and fire. Technically, the head of the class.
Excellent- This range is also of great beauty yet slightly more flexible regarding percentages. Many experts prefer the appearance of this range to Ideal.
Very Good- This range is balanced between precise proportions and price considerations. Viewed by many as the best overall value in beauty and price.
2. Deep Cut
When the cut of a diamond is too deep, some light escapes through the opposite side of the pavilion.
3. Shallow Cut
When the cut of a diamond is too shallow, light escapes through the pavilion before it can be reflected.
The cut, or proportion, of a diamond is measured in percentages relative to the diameter of its girdle. The girdle diameter of each diamond is always considered 100%. Example: The girdle of a diamond measures 10 millimetres (100%). The table measures 5.6 millimetres. The total depth measurement is 6.1 millimetres. The diamond would be described as having a table of 56% and a depth of 61%. The table and depth percentages are the key to determining good proportions.
The best colour is no colour. Diamonds allow light to be reflected and dispersed as a rainbow of colour. This light dispersion, or colour flash, has no effect on the technical grading of colour. The absolute finest colourless stone carries a D rating, descending through each letter of the alphabet to Z, designating a diamond of light yellow, brown, or gray. This body colour may be caused by the presence of trace elements, such as nitrogen, within the atomic framework of the carbon crystal. These trace elements are so minute that they are scientifically measured in parts per million. As the body colour becomes more intense, the grade for colour descends the scale. These gradations are so minute and precise that discerning a single grade under less than ideal laboratory conditions is extremely difficult. When directly comparing diamonds for colour, most consumers are unable to detect a difference unless they are at least two or three colour grades apart. We recommend selecting a diamond with a colour grade of I or better, and a yellow tint is visible for any colour from J-Z.
It is often surprising to learn that diamonds also occur by rare accidents of nature in shades of pink, blue, green, amber, or even red. These rarely occurring colours are referred to as fancies and are evaluated by a different set of colour standards. These standards take into consideration various factors such as hue and saturation. Fancy coloured diamonds are the most expensive because of their extreme rarity. Some fancy colours can cost hundreds of thousands of dollars for diamonds of one carat or less! Keep a lookout at large auction houses for prices
Almost all diamonds contain very tiny natural birthmarks known as inclusions. To determine a diamond's clarity, an expert views it under 10 power magnification. In addition to internal inclusions, surface irregularities are referred to as blemishes. These two categories of imperfections-inclusions (internal) and blemishes (external)-make up clarity.
The fewer the imperfections, the rarer and more valuable the diamond. Many inclusions are not discernable to the naked eye and require magnification to become apparent. A laboratory-certified clarity rating of SI2 represents the point at which inclusions are technically not apparent to the average naked eye.
Contrary to popular belief, higher clarity does not always mean more beautiful. If the inclusions are not visible to the naked eye, a higher clarity does not really improve the appearance of a diamond but rather the rarity and price. A higher clarity is more desirable and valuable, but knowing that you have selected the right clarity for the right reasons is most important. We recommend a clarity of SI2 or better.
Clarity is graded using a very precise and complex method of evaluating the size, location, and visibility of inclusions. The diagrams to the right show a top view of a round diamond. The inclusions, shown in red, are an approximate sample for each clarity rating. The plotted inclusions may not be actual size for display purposes. Remember, the inclusions depicted in red are not visible to the average naked eye until the I1-I3 clarities. Below is the technical clarity scale with a description of each term.
Most people compare carat weight to size. The larger the diamond the more it weighs. The weight of a diamond is expressed in carats. The word carat originated from the carob tree. The tiny seeds of this tree are well known for their uniformity and consistent weight. Traditionally diamonds and gemstones were weighed against these seeds until the system was standardized, and one carat was fixed at 0.2 grams. One carat is divided into 100 points. A diamond weighing one quarter of a carat can also be described as weighing 25 points or 0.25 carats. Points are generally not used to describe weights over one carat. Here are some examples of different weights for round diamonds and their corresponding sizes. These may not be actual size due to your monitor. The approximate girdle diameter is displayed in millimetres.
How Size Effects Rarity
The rarity of a diamond is greatly affected by its size. The rarity of a 1.00 carat diamond is much greater than twice that of a .50 carat. Although it only weighs twice as much, the 1.00 carat is statistically much more difficult (rare) to mine than the .50 carat. For an easy comparison of size, see the table next.
Diamonds are cut in many different and exciting shapes. The shape of a diamond is often confused with its cut. Shape refers to the basic form of the diamond: oval or pear shaped, for instance. Cut or proportions, on the other hand, refer to the ability of each of these shapes to reflect light. A round diamond, for example, could have a good cut or a poor cut depending upon its proportions. When it comes to shape, it is simply a matter of personal taste. The right shape for you is really the one whose appearance you prefer. Shape can be a statement of whom you are; like other areas of fashion, shape can reflect your individuality. The most popular shapes are displayed here, but many new and interesting shapes are being developed every year.