Dazed by Diamonds? Your 7 Diamond Questions, Answered

DIAMOND, this simple seven letter word resonates with people all around the world. We associate diamonds with love, affection, and the eternal promise of marriage. Diamonds are often displayed as status symbols, especially when used to encrust miscellaneous everyday objects or mounted in a musician’s forehead (yes, that happened recently). In countries where diamonds are mined and processed, these shiny little rocks represent a family’s livelihood.

For most people, purchasing a diamond is a process met with brightly lit display cases, friendly sales staff, and lots of diamond lingo that can be confusing and overwhelming. Perhaps you have heard of the 4 C’s?

As a GIA Graduate Gemologist and Registered Master Valuer, as well as having spent several years in retail jewellery sales, I have answered many questions about diamonds. Understanding how slight differences in quality can equate to a huge difference in price can be daunting when you are selecting the “perfect ring” for your future fiancé. Keep reading to learn more about the various factors that affect a diamond’s value and how a diamond’s quality is communicated.

Pear Shaped Diamond Ring
Pear Shaped Diamond Ring

What are the 4 C’s all about?

The Gemological Institute of America created the 4 C’s of diamond grading. The 4 C’s are COLOUR, CLARITY, CUT, and CARAT weight. Each individual grade directly influences the stone’s appearance as well as price.

COLOUR grades are based on the D-Z scale; D being colourless and Z being light yellow or brown. There are also blue, pink, purple, red, orange, and green coloured diamonds. These fancy coloured diamonds are graded on a slightly different scale that will be described in a future post.

CLARITY grades refer to the amount of inclusions (inside the stone) and blemishes (on the surface of the stone). There are very few diamonds that are “Flawless”. Most diamonds on the market today are “Slightly Included” to “Included”. Clarity characteristics are graded based on the number, size, nature (type of inclusion), position, and relief (contrast against the background).

CUT refers to the diamond’s proportions, polish, and symmetry. Although diamond faceting has evolved since its inception in 1380, Marcel Tolkowsky is often credited with the creation of the modern round brilliant cut, infact those same proportions are still used today. Cut determines how much light is returned to the viewer and will determine how “sparkly” the diamond looks. Polish refers to the stone’s actual surface quality while symmetry refers to the placement and alignment of the facets.

CARAT describes the weight of the stone. Don’t get confused between carat, carrot, and karat. Carrots are vegetables and karat describes the quality of gold (ex. 14 K or 18 Karat). One carat is equal to 0.2g. The word carat comes from the “carob seed” which was originally used to measure the weight of precious stones. You may also see carat weight expressed as 0.50 ct or 0.50ctw, the later meaning carat total weight or the combined weight of all stones within the item.

Now that you have an idea of what the grades represent, let’s look at some of the short hand you might see while shopping for a diamond. Perhaps you are looking at a diamond that is described as:

0.5 ct G SI1 EX

This means the diamond is half of a carat in weight (0.50 ct), near colourless (G), slightly included one (SI1), excellent cut (EX).

What is a Diamond Grading Report?

Diamond grading reports are used to document the quality grades of an unmounted diamond. Diamond grading laboratories, like GIA, issue reports that outline the stone’s 4 C’s. Other relevant information including a diamond plot (diagram of grade setting inclusions) and details about fluorescence and treatment may also be included. There are also Diamond Origin Reports that have additional details about where the diamond was mined.

Why do two reports for the same item have different grades?

As mentioned previously, when gemological laboratories grade diamonds, the stone is graded loose. This allows for the most accurate and detailed inspection of the stone. It also allows for the diamond weight to be calculated directly by weighing it.

Generally, appraisals for finished pieces of jewellery are completed without removing any stones. When evaluating mounted stones, the weight is estimated using measurements and standard formulas. The setting can disguise inclusions as well as influence the way the stone’s colour is viewed.

It is important to remember that appraisals are subjective and that the same item may be graded differently if viewed under different conditions or unmounted. Despite the challenges of grading mounted diamonds, there is still no excuse for large variances in quality grading. If the grades are within one grade up or down, it is still considered accurate. For example, if a stone was graded as VS2 by one person, a grade of VS1 of SI1 would also be acceptable. Significant variances should be questioned on both sides.

I1 Included Diamond
Inclusions in a diamond with a clarity grade of I1, GIA. Photo Credit: @acgemlab

Does GIA certify diamonds?

No, this is a common misnomer. GIA provides diamond grading reports. GIA does not provide any guarantee or statement of value for stones graded in their lab.

Which of the 4 C’s is the most important?

Each quality grade has an affect on the diamond’s value. Additionally, the most important factor for one client may not be the same for another. A client that wants a specific size stone may have to adjust the other quality grades to stay on budget. Another client may want the highest clarity stone, but isn’t so picky about size. It all depends on what your exceptions are and what your budget will allow. Overall, a well cut stone will always have a nice appearance.

Why do two stones with the same grade on paper look totally different?

“Every diamond is as unique as the wearer” is so true. No two diamonds are exactly the same. Although stones may have the same grade, the grade setting characteristics will vary. Most diamonds available in the market are slightly included to included (SI-I). Diamonds in these categories have inclusions that are noticeable to obvious to the unaided eye. However the position, size, number, nature, and relief will vary from one stone to the next. When deciding between two stones, make your final decision by looking at the actual diamond and not the report paper. Your eye will be drawn to the more lively stone. Remember that a diamond ring will be worn on the finger, not a diamond grading report.

Can you buy diamonds online?

What can’t you buy online these days? There are a bunch of online retailers that sell diamonds directly to the public. Low overhead costs allow online retailers to offer highly competitive prices. The most important thing to consider when buying online versus buying from a local retailer is service. In the future you will need to have the item cleaned and checked regularly. What about repairs or ring sizing? Perhaps the online retailer offer these services, but will need to send the item away for an undetermined amount of time and pay for shipping and insurance costs? Make sure that you will receive the kind of service you expect and deserve from the retailer before your buy.

Any other advice?

Once you have found the perfect stone, make sure that you have the item appraised by a professional jewellery appraiser. The appraisal will be required to obtain insurance and will provide peace of mind while the item is proudly worn and showed off.

Written By: Alanna Campbell, May 8, 2021.

Opinions and experiences are my own.