Diamond Buyer's Guide

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Before you start buying diamond jewellery, you want to have an understanding of what you're buying. This guide simplifies the four Cs of diamonds - cut, colour, clarity, and carat weight, so you can select your diamond based on the same criteria jewellers use to grade them.

After reading through this guide, you'll be ready to choose the diamond that's right for you.


The cut of a diamond has the most effect on its sparkle, or brilliance. Even if the diamond has perfect colour and clarity, a poor cut can make a diamond look dull. Bespoke Diamond only uses the highest grades of diamond cut, for the most sparkle. Learn how to choose the right diamond cut with the most brilliance for your budget.

The cut of a diamond - its roundness, its depth and width, the uniformity of the facets - all determine a diamond's brilliance. Many gemmologists consider cut the most important diamond characteristic because even if a diamond has perfect colour and clarity, a diamond with a poor cut will have dulled brilliance.

The width and depth have the greatest effect on how light travels within the diamond, and how it exits in the form of brilliance.

Too Shallow: Light is lost out the bottom causing the diamond to lose brilliance.
Too Deep: Light escapes out the sides causing the diamond to appear dark and dull.

Correct path of light through a well cut diamond.

The diamond's proportions, specifically the depth compared to the diameter, and the diameter of the table compared to the diameter of the diamond, determine how well light will reflect and refract within the diamond.

Diameter: The width of the diamond as measured through the girdle
Table: The largest facet of a gemstone
Crown: The top portion of a diamond extending from the girdle to the table.
Girdle: The narrow band around the widest part of a diamond.

Pavilion: The bottom portion of a diamond, extending from the girdle to the culet.
Culet: The facet at the tip of a gemstone. The preferred culet is not visible with the unaided eye (graded "small" or "none").
Depth: The height of a gemstone measured from the culet to the table.
Polish and Symmetry

Polish and symmetry are two important aspects of the cutting process. The polish grade describes the smoothness of the diamond's facets, and the symmetry grade refers to alignment of the facets. With poor polish, the surface of a facet can be dulled, and may create blurred or dulled sparkle. With poor symmetry, light can be misdirected as it enters and exits the diamond. The polish and symmetry grades are clearly listed in each diamond detail page and within the diamond grading report. For the most beautiful diamond, look for a symmetry grade of ideal (ID), excellent (EX), very good (VG), or good (G). Avoid diamonds with symmetry grades of fair (F) or poor (P), as the alignment of their facets may misdirect light so severely that it affects the brilliance of the diamond.

Bespoke Diamonds only uses diamonds with a minimum of Very Good/Very Good Polish/Symmetry grade.

Diamond measurements are calculated and applied to a cut grading scale that makes it easy to understand how well each reflect light:

Ideal cut: Represents roughly the top 3% of diamond quality based on cut. Reflects nearly all light that enters the diamond. An exquisite and rare cut.
Very good cut: Represents roughly the top 15% of diamond quality based on cut. Reflects nearly as much light as the ideal cut, but for a lower price.
Good cut: Represents roughly the top 25% of diamond quality based on cut. Reflects most light that enters. Less expensive than a very good cut.
Fair cut: Represents roughly the top 35% of diamond quality based on cut. Still a quality diamond, but a fair cut will not be as brilliant as a good cut.
Poor cut: This includes all diamonds that do not meet the proportion standards of a fair cut. These diamonds are deep and narrow or shallow and wide and tend to lose most of the light out the sides and bottom.

Bespoke Diamonds only uses diamonds with a minimum of Very Good cut grade.


Diamonds with very little colour are the most highly valued and are priced accordingly. A little colour can diminish a diamond's brilliance. To help you choose the most brilliant diamond, Bespoke Diamond offers diamonds with the highest grades of colour. Learn how to choose a diamond with no colour noticeable to the unaided eye.

Acting as a prism, a diamond can divide light into a spectrum of colours and reflect this light as colourful flashes called fire. Just as when looking through collared glass, colour in a diamond will act as a filter, and will diminish the spectrum of colour emitted. The less colour in a diamond, the more colourful the fire, and the better the colour grade.

D: Absolutely colourless. The highest colour grade, which is extremely rare.
E: Colourless. Only minute traces of colour can be detected by an expert gemmologist. A rare diamond.
F: Colourless. Slight colour detected by an expert gemmologist, but still considered a "colourless" grade. A high-quality diamond.
G-I: Near-colourless. Colour noticeable when compared to diamonds of better grades, but these grades offer excellent value.
J-L: Slight-colourless. Colour detectable.
M-Z: Tinted Colour

Note: Strongly coloured diamonds are termed fancies and are extremely rare and desirable.


Some people seek diamonds that produce this unique effect, while others definitely avoid it. The visible effects of fluorescence grades of faint, inert, negligible, and medium, can only be detected by a trained gemmologist. A fluorescence grade of strong or very strong can make a diamond with a near-colourless grade look even whiter yet in some instances give the diamond a slight hazy or oily appearance. Diamonds with a strong or very strong fluorescence are priced slightly lower than other diamonds.

Bespoke Diamonds only uses diamonds colour graded from D to I and with no fluorescence.


Diamonds with few flaws, or inclusions, are very rare and highly valued. Clarity is graded based on the number, location, size, and type of the inclusions found in a diamond. Bespoke Diamond has some of the clearest diamonds available. Learn how to choose the right grade of clarity for your diamond.

Diamonds that are absolutely clear are the most sought-after and therefore the most expensive. But many diamonds have inclusions - scratches, trace minerals or other tiny characteristics that can detract from the pure beauty of the diamond. The GIA use a detailed system of rules and standards to summarize the number, location, size, and type of inclusions present in a diamond.

FL, IF Diamonds: Flawless: No internal or external flaws. Internally Flawless: No internal flaws. Very rare and beautiful diamonds.
VVS1, VVS2 Diamonds: Very, Very Slightly Included: Very difficult to see inclusions under 10x magnification. An excellent quality diamond.
VS1, VS2 Diamonds: Very Slightly Included: Inclusions are not typically visible to the unaided eye. Less expensive than the VVS1 or VVS2 grades
SI1, SI2 Diamonds: Slightly Included: Inclusions are visible under 10x magnification, and may be visible with the unaided eye. A good diamond value.
I1, I2, I3 Diamonds: Included: Inclusions are easily visible under 10x magnification, and be visible with the unaided eye.

Bespoke Diamonds only uses diamonds from Flawless to SI as we feel diamonds of lower grades look dull and have no place in quality jewellery.


The weight of a diamond is measured in carats. Since larger diamonds are rarer than smaller diamonds, diamond value tends to rise exponentially with carat weight. Read more about carat weight and learn how to balance diamond quality with the size of your diamond

Once you've determined what cut, colour, and clarity grade you're looking for in a diamond, it's easy to determine the carat weight of diamond that will fit within your budget.

This chart illustrates how diamonds of different carat weights look when set in a ring. Note that a 2-carat diamond does not appear to be twice the size of a 1-carat diamond when viewed from the top.

When diamonds are mined, large gems are discovered much less frequently than small ones, which makes large diamonds much more valuable. In fact, diamond prices rise exponentially with carat weight. So, a 2-carat diamond of a given quality is always worth more than two 1-carat diamonds of the same quality.

To choose the best carat weight of diamond, consider your partners style, the size of their finger, the size of your setting, and your budget.

    * If you have a set budget, explore all your options and you'll find that there is a wide range of diamond carat weights and qualities available in your price range.
    * If your recipient is very active or not used to wearing jewellery, they may find themselves bumping or nicking their new ring. Consider a smaller size diamond or a setting that protects a larger diamond from getting knocked against doors and counters.
    * Also keep in mind that the smaller the finger, the larger the diamond will appear. A 1½-carat diamond solitaire looks much larger on a size G finger than a size U.
    * If you have already chosen a setting, make sure you choose a diamond to fit. Look for the diamond size specifications of your ring or ask your Bespoke Diamond consultant what size diamond you should look for.


The most important step in choosing a diamond is reviewing the diamond certificate, referred to by diamond grading labs as a grading report. A grading report documents the characteristics of a diamond, like the four Cs. Before purchasing a diamond, make sure it has a grading report from a reputable laboratory, as this is your guarantee of quality for that diamond.

Bespoke Diamonds only sells certificated diamonds from reputable associations.


Diamonds are the hardest substance on earth. They are uniquely resistant to damage by heat or scratching, and can be cut or polished only by another diamond - but an extremely hard blow to the girdle can cause a diamond to chip. By having your diamond set in a relatively protective setting, and remaining conscious of it on your finger, you can keep your diamond intact for a lifetime. Exposure during ordinary wear to perspiration and household chemicals, like chlorine and hairspray, can cause build up that dulls the surface of a diamond. We suggest periodic cleanings to keep the diamond brilliant and refractive.

A solution of one part ammonia and six parts water can be used to clean diamond jewellery at home. If cleaning by hand, gentle scrubbing with a soft brush should loosen most dirt and greatly increase the brilliance of the diamond, but be careful not to scratch the metal of your setting. Once a year, it is a good idea to have your diamond cleaned and have the security of the setting checked.

We recommend that all diamond jewellery is stored individually in soft cloth pouches when not being worn to prevent the diamond or diamonds from scratching or dulling other jewellery.

Bespoke Diamonds offers yearly checks, cleaning, polishing on all diamonds sold. 
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