Buyer’s Guide

When buying that special piece of diamond jewellery you must first consider the type and quality of loose diamonds that are required for you customized diamond jewellery. In any purchase a budget must be set and in most diamond rings and jewellery the diamonds will make up the majority of the cost. So naturally selecting the diamond should be the place to start the buying process. By learning about correct diamond selection it will give you the knowledge to make an informed decision with you purchase. Understanding selection will make sure you correctly choose a diamond perfectly suited to your individual needs and avoiding future disappointment and most importantly saving you money.

As much as everyone would love to own a flawless perfect in every way diamond a realistic approach needs to be taken when choosing a diamond. Unlike most other precious gems, diamonds can be precisely measured and categorized into a ridgid quality and price structure using the 4 C’s of diamond grading. Once you have viewed a number of different diamonds to visually see the difference between qualities, choosing a diamond can become quite simple. By evaluating each of the 4 C’s we can balance each f these qualities to find the diamond that will match our budget and satisfy or requirements.

Carat Weight

Of the 4 C’s carat weight is the most common place to start when choosing a diamond. When looking to buy a diamond most people will have a fair idea of the size diamond they would like their partner to wear. In most cases people will use a 1ct diamond as their reference to the size they would like to achieve. Once the client has set on a size range it is then a matter of balancing the other three grading categories to achieve that size diamond with the budget the client has nominated.

As the size of a diamond increases the price of a diamond will rise exponentially. For example if a 0.50ct diamond is $2500 then a 1.0ct diamond if the same grade will be $8000 and a 2ct diamond will be $28000. Like all for the grades carat weight is a personal decision as to what the client feels will satisfy their expectations. When visually selecting a diamond it actually takes a difference of 0.15-0.25ct in weight to actually see a significant change in size between two diamonds. Therefore needing such a large change in size often will considerably alter the price bracket a diamond will rest in, often forcing our budget into a specific size category.

Cut Quality

The cut of a diamond does in part have to do with the shape of a diamond. Shape does affect the price of a diamond with round diamonds being the most expensive cut and the other fancy shapes falling below at varying levels. This is because round diamonds are the most brilliant and have the most specific scientific grading specifications for a perfect cut. The most important aspect of the cut quality is the proportion to which a diamond is cut. The proportion and symmetry of a diamond determines how well a diamond will refract the light producing the scintillation and brilliance a diamond should display.

The quality of the cut is very important not only to how a diamond will look but also how the diamond displays it’s colour and hides the clarity of the diamond. Cut also plays a very significant role in the price of a diamond altering the price in some cases up to fifty percent. As the quality of a diamond’s cut involves several minor and major factors it can be a little difficult for the average customer to establish this quality. The best way to check a diamond’s cut is to buy a diamond with a reputable certificate.

Diamond certificates have two to three final grading scores that take all the measurements of the diamond and summate them into a verbal scale. The categories are Cut, Finish and Symmetry graded to either Excellent, Very Good, Good or Poor. The Finish of a diamond is how well the surface of the diamond is refined and polished to remove graining and scratches off the facets. This is probably the least important category with even a “Good” grade being quite an acceptable purchase. The cut is the measurement of the proportions to which the diamond is cut and the overall performance of the diamonds brilliance. A poorly cut diamond will often be smaller in diameter and holding extra weight at the base of the diamond. Although it may look impressive under the intense lights of a showroom, in natural light much less of the light is refracted directly back through the top of the stone.

The difference between an “Excellent” and “Very Good” quality cut is only slight but does become apparent above a carat weight of 0.80ct to a discerning eye. A “Very Good” cut is quite acceptable for most clients looking for a high quality diamond. They are very near to perfect proportions in all of the measured quantities and produce an exceptionally brilliant diamond. For those clients wanting absolute perfection where every facet of the diamond is visually stunning an “Excellent” cut and symmetry is essential.

A diamond’s symmetry grades the relationship of the facets. How proportionate they are in size and relation to each other. Each corresponding facet should lie on exactly the same angular plain and be the same size. When the symmetry is perfect each facet can be seen individually and you can see the perfect alignment with the naked eye. Without a precise symmetry a diamond’s sparkle with be uneven and the facets will be indiscernible. When both the cut and symmetry are of a “Very Good” to “Excellent” grade any inclusions the diamond may have are disguised extremely well and how the diamond presents it’s colour can be improved by up to two grades. We believe that when selecting a diamond that Cut quality is the most essential decision to be made regarding the 4 C’s as it can have the greatest influence on the other three grades and is not commonly explained by retail sale consultants.

Colour Grade

A diamond of perfect colour is completely transparent and devoid of any colour pigment and are very rare. Diamonds can contain a slight amount of pigment before they start to visually display any tint of colour. Diamonds in the white colour grading scale range from colourless to hues of yellow or brown. To be a true white diamond that will not display any tint of yellow or brown it must have a grade between D and I.

Generally accepted as standard white are diamonds of “G or H” colour. With a quality cut they will always stand out from an average diamond while not being overshadowed by diamonds on the top tier. These two colours are a good balance for quality and budget consciousness. When size and cut start to stretch the budget an “I” colour will still give the client an acceptable result but it is on the borderline of a true white diamond. Often when the right size and cut has been achieved the best area to spend any additional money is to improve the colour. Diamonds graded from “D – F” are considered exceptionally white. When you want a diamond that will standout above all others this is the choice that will visually improve the appearance of your diamond.

Clarity Grade

Clarity is a visual judgment under magnification of the size, type and position of imperfections contained within a diamond. Diamonds are graded from internally flawless to highly visually included. Most diamonds contain some type of inclusion and the way a diamond is cut is designed to help hide these marks within the facets of the diamond. All diamond clarities graded from VVS1 – SI2 are considered to be non-visible to the naked eye and will all look exactly the same when set in a ring. Therefore this is the best category to sacrifice in order to minimize cost and better the other qualities of the diamond.

Once viewed most clients are comfortable to purchase a diamond of VS1-SI1 clarity grade. Within these grades the inclusions can be seen by the clients under magnification without appearing unsightly or disrupting the scintillation of the diamond. A diamond with a clarity grade of SI2 is again where we consider to be a borderline decision. If the budget is being squeezed an SI2 clarity can still be fine but often a hint of the inclusion can be seen by a trained eye and is better to be avoided if you have any concerns. Clarity grades above VS1 are all very small and only increase the price because of the rarity of their occurance. Clients choosing a diamond in this range should have already chosen a diamond at their required size of top cut and colour and are looking to buy the perfect diamond where price is not a consideration in the purchase. Our suggestion for quality and budget consciousness is an SI1 clarity for round type diamonds and VS2 for square type diamonds.


The combination of the four C’s is what ultimately determines the price of a diamond. And the best confirmation of the quality of the diamond is an independent international laboratory certification. However care must be taken to the certifier used for the chosen diamond as all have a different set of standards to grade against. GIA and HRD are the most common and highest regarded certifiers with IGI and DCLA in the mid range and EGL and AusCert being very lenient in their standards.

The better regarded the certifier the more it can potentially be worth in the market. As it is often the cutting factory that sends the diamond out for certification they will know the general quality of the diamond and send it where that particular diamond will receive the highest rated grading. Their best diamonds will go the the strictest and best certifiers and any poorer quality stones will be sent where they will get the most leniency. This will achieve the best grade possible and result in the most money for each diamond. To get a true indication of the quality of the diamond we suggest only buying a diamond certified by either GIA or HRD who are highly as the premier certifiers.