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Diamond Shoppers Guide

Diamonds are pure or nearly pure carbon, blessed with three extraordinary qualities. First, a diamond is the purest of earth's gemstones, composed of a single unadulterated element. Second, it is the hardest transparent substance known to man. However, sharp impact may cause damage to a diamond. Third, a diamond has unique powers of light reflection. When cut to proper proportions, it gathers light within itself, sending it back in a shower of fire and brilliance.

Many people are confused about how diamonds are priced. The best explanation is that asking for the price of a diamond is like asking for the price of a house. A real estate agent can’t quote you a price for a house without knowing its size, condition, location, etc. The same process is used while buying a diamond as well. A diamond’s beauty, rarity, and price depend on the interplay of all the 4Cs—cut, clarity, carat, and colour.

The 4Cs are used throughout the world to classify the rarity of diamonds. Diamonds with the combination of the highest 4C ratings are more rare and, consequently, more expensive. No one C is more important than another in terms of beauty and it is important to note that each of the 4Cs will not diminish in value over time.

Once you have established those 4C characteristics that are most important to you, a jeweller can then begin to show you various options with quoted prices.

Carat

Carat is often confused with size even though it is actually a measure of weight. One carat is equivalent to 200 milligrams. One carat can also be divided into 100 "points." A .75-carat diamond is the same as a 75-points or 3/4 carat diamond.

A 1-carat diamond costs exactly twice the price of a half-carat diamond, right? Wrong. Since larger diamonds are found less frequently in nature, which places them at the apex level of the Diamond Quality Pyramid, a 1-carat diamond will cost more than twice a 1/2-carat diamond (assuming colour, clarity and cut remain constant).

Cut and mounting can make a diamond appear larger (or smaller) than its actual weight. So shop around and talk to your jeweller to find the right diamond and setting to optimise the beauty of your stone.

Clarity

Clarity describes the clearness or purity of a diamond. Clarity is determined by the number, size, nature, along with location of the internal (inclusions) and external (blemishes) imperfections. Inclusions are natural identifying characteristics such as minerals or fractures, appearing while diamonds are formed in the earth. They may look like tiny crystals, clouds, or feathers.

To view inclusions, jewellers use a magnifying loupe. This tool allows jewellers to see a diamond at 10x its actual size so that inclusions are easier to see. The position of inclusions can affect the value of a diamond. There are very few flawless diamonds found in nature, thus these diamonds are much more valuable.

Inclusions are ranked on a scale of perfection, known as clarity, which was established by the Gemmological Institute of America (GIA). The clarity scale, ranging from F (Flawless) to Included (I), is based on the visibility of inclusions at a magnification of 10x.

The clarity scale is broken down into the following grades in accordance with the GIA (Gemmological Institute of America) and EGL (European Gemmological Laboratory) standards.

It is important to note that the GIA Grading system is not static, and has changed slowly over the time.

A mounting, thus having little effect on the beauty of a diamond, can hide some inclusions. An inclusion in the middle or top of a diamond could influence the dispersion of light, sometimes making the diamond less brilliant.

The greater a diamond's clarity, the more brilliant, valuable and rare it is—and the higher the quality it is.

Be aware! Two methods used to enhance the clarity grade given to a diamond are laser drilling and fracture filling. Laser drilling is the process in which a laser is used to drill a tiny hole into a diamond and the black of the imperfection is then removed. The second treatment is fracture filling. This method is not permanent and therefore not recommended. All clarity treated diamonds must be disclosed as such before sale. Before buying, just check with the vendor whether they are clarity treated or not.

Colour

Colour describes the amount of colour the diamond contains. This can range from colourless to yellow with slight tints of yellow, grey, or brown. Colours can also range from intense yellow to brown, blue, green, pink and red. These fancy colours are rare and therefore more valuable.

Warmer coloured diamonds (K–Z) are particularly desirable when set in yellow gold. Icy winter whites (D–J) look stunning set in white gold or platinum.

Colour differences are very subtle and it is very difficult to see the difference between, say, an E and an F. Therefore, colours are graded under controlled lighting conditions and are compared to a master set for accuracy.

Truly colourless stones, graded D, treasured for their rarity, are highest in quality. Colour, however, ultimately comes down to personal taste. Ask a jeweller to show you a variety of colour grades next to one another to help you determine your colour preference.

Be aware! It is possible to influence the colour by irradiation treatment followed by heat treatment. This method is not recommended for two reasons. The first is the risk involved with exposure to irradiated objects. The second is the risk of colour change over time. All colour treated diamonds must be disclosed as such before sale.

The colour of the stone can be determined by using an EGL (European Gemmological Laboratory) or GIA (Gemmological Institute of America) Certified set of master stones and/or the Colorimeter, a computer which accurately grades the colour of a polished diamond.

Cut

Cut refers to the proportions, finish, symmetry, and polish of the diamond. Based on scientific formulas, a well-cut diamond will internally reflect light from one mirror-like facet to another, disperse, and reflect it through the top of the stone. This results in a display of brilliance and fire, thereby makes well-cut diamonds expensive than deep or shallow-cut diamonds. Diamonds that are cut too deep or too shallow lose or leak light through the side or bottom, resulting in less brilliance and ultimately, value.

Cut also refers to shape—round, square, pear, or heart for example. Since a round diamond is symmetrical and capable of reflecting nearly all the light that enters, it is the most brilliant of all diamond shapes and follows specific proportional guidelines.

Non-round shapes, also known as "fancy shapes," will have their own guidelines to be considered well cut.

With the advent of technology, the cut of the diamond can be determined using the Dia-Mension system, a computerized system that takes accurate measurements and proportions of a diamond in seconds, in addition to the standard millimetre gauge.

Since the quality of the cut is directly responsible for the stone's beauty, the precision with which the facets are arranged is of prime importance. They determine the amount of light reflected to the eye, called brilliance.

The proportions displayed by the stone are very significant. Two of the key factors in the grading of cut quality -- table percentage and depth percentage -- are usually expressed on grading reports. Measurement of three different parameters allows for easy calculation of these percentages by using the formulas listed below.

For example, for a round brilliant cut diamond, table percentage is calculated as follows:

Table (%) = longest table measurement (in mm)/average girdle diameter (in mm)

And depth percentage = depth (in mm) / average girdle diameter (in mm)

Without attention to quality cutting, light is lost and not returned to the eye. The following is the list of EGL Proportions Criteria.

Each cut style above represents, in the opinion of its respective designer, those proportions, which best balance the qualities of brilliance and dispersion ("fire") within a round diamond.

Which ‘C’ is the most important?

A diamond's quality depends on a combination of all the four "C's". However, cut is believed as the most critical of these four Cs. More than any other factor, cut determines the brilliance, fire, and overall beauty of your diamond.

The 5th C: Confidence

A good jeweller is the first step to a smart diamond purchase. To find a jeweller you can trust, ask your family and friends for recommendations. Your jeweller should be knowledgeable about diamonds and help you feel comfortable making this important purchase.