Diamond 4 C's

A guide to quality & value

Born billions of years ago deep within the earth, diamonds are the hardest natural substance known to man.

The shape you select is a matter of individual taste. However, the precision with which each diamond is cut and polished determines its brilliance, fire and ultimate beauty, and ultimately, its value.

Each diamond is unique. At first glance two diamonds may appear to look similar, but each has its own individual characteristics that determine the value. These are known as the 4Cs:

Cut

Color

Clarity

Carat weight

Diamonds with the most perfect combination of the 4Cs are the rarest and most valuable in the world.

The Cut

The cut of a diamond is what determines how much fire and brilliance the diamond will exude. While nature determines the color and clarity of a stone, the cut is dependent solely upon the skill of the cutter.

The depth and table percentages, which make a diamond an ideal or good cut, vary from shape to shape. A diamond that is cut too shallow with respect to its width will allow too much light to pass straight through the diamond, leaving little light to reflect. Such a diamond will appear dull and lacking in brilliance. Conversely, a diamond cut too deeply will allow light to escape from the sides of the diamond, also appearing dull.

All the facets should be highly polished and correctly shaped. A poorly polished diamond lacks brilliance. Proportion problems are often seen in diamonds graded as Fair or Poor - they can include severe misalignment of facets, a noticeably off-center table, a noticeably 'wavy' girdle, or a table which is noticeably not parallel to the girdle.

In order to cut a stone to ideal proportions, much of the rough diamond is sacrificed, leaving a stone with a smaller carat weight. Diamond cutters sometimes sacrifice ideal proportions to end up with a larger, more profitable stone.

Consequently, ideal cut stones are very rare and hard for wholesalers and retailers to find, and as the consumer, you will see that retail jewellery stores price accordingly.

To obtain a diamond that has the most brilliance then choose a cut grade of ideal or very good and proportions of ideal or excellent.

For the best value, choose an ideal or very good cut with proportions of ideal or excellent. You might then consider less expensive grades of color, such as G- H and a clarity grade of SI1 - SI2.

 

Color

The color of a diamond has a significant impact on its value. The rarest diamonds have no trace of color at all. These are extremely uncommon as most diamonds have a slight trace of color be it yellow or brown.

The color scale ranges from D to Z, from colorless to light yellow, respectively. The farther from colorless that a diamond's grade is, the less rare and therefore less valuable it is.

When buying a diamond, take into consideration that it is often very difficult to detect the difference between a colorless diamond (D-F) and a near colorless diamond (G-H), especially when it is mounted in jewellery. Diamonds with a J color grade usually have yellow shading that can be detected by the naked eye. However, a well cut stone with good proportions will still release the brilliance and fire of a lower colored diamond, dispersing light in such a way that it lends to a beautiful stone.

If you can afford it choose a colorless diamond with a grade of D- F. For excellent value choose a diamond with no noticeable color to the unaided eye with a grade of G - I.

Diamonds also come in a range of natural fancy tones, such as blue, pink, green, and red. Such diamonds have so much color that they are not graded on the normal scale D-Z. Believe it or not, these fancy diamonds are particularly rare, and like their colorless counterparts, can also come attached to a high price tag. Bear in mind that color does not have an exclusive impact on a diamond's value. The value of a stone is affected by a combination of qualities including shape, clarity, cut, and carat weight, as well as its color.

Though fancy colored diamonds occur rarely in nature, with modern science they can occur quite readily in a laboratory . Irradiated diamonds are natural colorless diamonds that have been treated with a special combination of radiation and intense heating to color the stone. The treatment creates a permanent color change, and leaves no harmful traces of radiation on the diamond. Even though they are still real diamonds, irradiated fancy colored diamonds have a lower value than naturally occurring fancy colored diamonds. They can be detected though using spectroscopic analysis .

Clarity

When gemologists inspect diamonds for overall quality, they must painstakingly determine the clarity of the diamond.

Using a 10x magnification loupe, gemologists determine the size, type, and position of the imperfections. Members of the industry refer to these imperfections as "inclusions." Gemologists then put the stone into one of the following classifications based on the results of their inspection:

Within the VVS, VS, and SI classifications there are additional gradations denoted by a number 1 or 2. In the case of the Included class, the subdivisions are denoted with a number from 1 to 3. Because most diamonds have flaws, stones with clarity between FL-VVS2 are considered particularly rare and are consequently particularly pricey.

We recommend selecting a diamond that has no inclusions visible to the naked eye, such as VS1 and VS2. This grade is significantly lower in price than flawless diamonds and will not contain any inclusions that would otherwise distract from the beauty of the diamond.

In some cases, cutters may choose to use certain treatments in order to improve the clarity grade of a diamond.

Laser Drill Holes: Laser drill holes are one of the few man-made inclusions that can occur inside a diamond. Drilling this type of hole into a diamond can actually raise its clarity grade. In some diamonds, the clarity grade may be determined mainly by the presence of just one or two dark included crystals in a diamond that is otherwise relatively free of inclusions. In certain circumstances, the diamond cutter will decide to use a procedure to remove the dark inclusions and, hopefully, increase the clarity of the diamond.

Fracture Filling: Fracture filling is a process that is performed on certain diamonds which have white feathers that reach to the surface of the stone. To reduce the appearance of the feather, thereby making the clarity seem higher, some cutters or jewellers will force a liquid into the diamond through this fracture. The liquid then hardens to a clear solid, filling the fracture and reducing its appearance under magnification. Because this particular type of treatment is not permanent, and because many in the diamond trade regard it as a somewhat deceptive practice, most laboratories (including GIA and AGS) refuse to grade diamonds that have been fracture filled. Jewellery 247.co.uk does not sell fracture-filled diamonds.

Carot Weight

A carat is the unit of measurement which the jewellery industry uses to weigh diamonds. One carat is equal to .20 grams. Often diamond weight is declared in points. One carat is equal to 100 points. Thus, a .75 carat diamond is equivalent to 75 points.

The price of a diamond will always rise proportionately to the size of the stone. Large diamonds are rare and have a greater value per carat. So, in terms of points, remember that a one-carat diamond will cost much more than a 95 pointer.

The use of the word carat dates back to ancient times when the carob seeds were used to balance the scales. The seeds were extremely accurate. They were tiny horned shaped and uniform in weight. The term carat is entirely different to the carat used to describe gold, which actually measures purity and not weight.

Do not buy into the belief that the larger the carat weight, the more valuable the diamond. While this can be true, it is not necessarily so.

Keep in mind that diamond dealers take into account a stone's colour, clarity, and cut, as well as carat weight when pricing a diamond and often their pricing is subjective. For that reason, it is important for every potential diamond buyer to priorities each of the aforementioned characteristics when considering a stone.