Your Guide to Choosing the Perfect Diamond

Diamonds are among nature’s most incredible creations and are without a doubt the most popular, infamous, and sought-after gemstone in the world. Natural diamonds possess an array of unique features that are graded in order to easier classify and value individual stones. When choosing your perfect diamond it’s important for you to carefully consider each grading element against your budget and your desired look before making your choice.

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Diamond Grading: The Four C’s

The value of a diamond is determined by careful examination and grading using the ‘four C’s’ of diamonds; cut, colour, clarity, and carat. Fine-tuned over the decades, the term originated in 1940s America. Developed as a mnemonic device to help gemmology students remember the four factors that characterise a faceted diamond, the concept was revolutionary.

Of the four C’s of diamonds, two are determined by nature, and two are determined by the human manufacturing the rough stone. Nature shapes colour and clarity, while humans choose which of these to prioritise when selecting the cut and carat. Depending on the rough stone, the cutter may choose to cut away imperfections (known as inclusions or blemishes) to get a high-clarity stone, or they may try to keep the diamond as large as possible to maximise the carat weight


The grading scale for cut evaluates how a cut diamond interacts with light to deliver the brightness and reflective appearance that is so sought-after. When a diamond is well cut it reflects brilliant light back to the eye and creates the stunning sparkling effect diamonds are so famous for.

The scale ranges from Excellent to Poor and is based on a round brilliant cut diamond. This cut maximises the amount of light reflected due to the number of facets (flat surfaces) of the stone.

Other cuts of diamonds such as emerald feature fewer facets, so while remaining a stunning stone they will reflect less brilliance.

Cut may also refer to shape, such as princess, teardrop, pear, oval, etc. These are referred to as ‘fancy’ shapes, and come down to personal taste and preference. Each of these cuts have its own proportions they are graded against.


When grading the colour of a diamond, the grader is actually measuring the absence of colour on a scale from D-Z. The grade is established in controlled viewing conditions and in comparison to master stones, with D referring to a colourless, exceptional white diamond, and Z being ‘fancy’ yellow or tinted.

This scale is only used to grade ‘white’ diamonds, while fancy or coloured diamonds use a different system that grades them on the intensity of their colours, as opposed to the lack of. Generally, if a diamond presents more yellow or brown tones than a Z master stone, it will be classified as fancy.

Using this scale, the whiter and less colour a diamond presents the higher the value and price. While D is considered the most valuable, the difference in colour to the naked, untrained eye between a D and a G grade diamond is almost invisible. This is important to remember when choosing your perfect diamond, as it may be more achievable than you think.


As natural diamonds are created by the Earth, no two stones are alike. The tremendous heat and pressure required to produce diamonds results in the presence of internal characteristics referred to as inclusions, and external characteristics referred to as blemishes.

While no diamond is perfectly pure and unblemished, the closer it is to purity, the better its clarity. Clarity grading features 6 categories, which a diamond will be placed into after careful, close inspection under 10x magnification:

  • Flawless – no inclusions or blemishes visible
  • Internally flawless – no inclusions visible
  • Very, very slightly included (VVS1 and VVS2) – inclusions are so slight they’re difficult for a skilled grader to see
  • Very Slightly Included (VS1 and VS2) – minor inclusions are present
  • Slightly included (SI1 and SI2) – inclusions are noticeable
  • Included (I1, I2, and I3) – inclusions are obvious and may affect transparency and brilliance

It’s important to note that many diamonds of lower clarity grading may still appear completely clear to the naked eye. Choosing a diamond with a lower clarity grade could potentially be a far more attractive option while still receiving a brilliant, beautiful diamond.


Diamonds are sold by weight using the unit of measurement known as carats. Used across the world for the buying and selling of diamonds, one metric carat is equal to 200 milligrams. Subdivided into a 100-point system, a .25 carat diamond would be referred to as a ‘twenty-five pointer’.

While it may be easy to get caught up in sizes, when speaking about diamonds bigger is not always better, and heavier diamonds aren’t necessarily more expensive. It’s important to remember that each of the four C’s is a factor in a diamond’s price, and two diamonds of the same carat weight may have very different price tags depending on their clarity, colour and cut.

Diamond Fluorescence

Fluorescence refers to the visible light some diamonds emit when they’re exposed to ultraviolet (UV) light.

Approximately 25-35% of diamonds exhibit some degree of fluorescence, and in more than 95% of these diamonds, the visible colour is blue. As it is somewhat less known, diamond fluorescence is often misunderstood, and many misconceptions exist about what it truly is.

  • Diamond fluorescence is not an indication that a diamond is real – many lab-grown diamonds and cubic zirconias have indicated fluorescence, while many natural diamonds show no fluorescence
  • Diamond fluorescence has little to no effect on a diamond’s sparkle, and research shows that it doesn’t impact beauty
  • Diamond fluorescence has no effect on a diamond’s colour grading

In most cases, you will not be able to tell the difference between a diamond that shows fluorescence and one that does not. Your choice will ultimately come down to personal preference

Understanding Diamond Prices

Buying diamonds can be confusing since two diamonds of the exact same weight can vary in price by thousands of dollars. Diamonds are sold by weight, but their value is determined using each of the four C’s as well as market influences such as demand, inflation, and consumer confidence.

When purchasing loose diamonds or a diamond ring, you will need to decide where your priorities lay. You may prefer a smaller, brilliant diamond with high clarity and few inclusions, or a larger stone with lower clarity, but more wow factor. Diamond quality and characteristics also vary depending on their country of origin.

At Atelier Diamant, we source diamonds from all over the world and buy direct from diamond cutters in order to offer you a more cost-effective custom jewellery experience. As certified diamond graders and qualified gemmologists, our expert advice can help you get the most out of your budget.

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Let us find the right diamond for you


Purchasing and selecting diamonds is a deeply personal and exciting privilege! We’re passionate about empowering you to choose a diamond you will delight in owning and wearing for many years to come.

As diamond wholesalers, during your initial consultation at our Perth studio, we obtain a thorough understanding of your desires and budget for your dream diamond. From here, we source the stone that best matches your preferences for cut, colour, clarity and carat, complete with a grading certificate.

Whether you’re looking to purchase loose diamonds, or source the perfect diamond for a custom-designed diamond engagement ring, we’re here to help. Book a consultation to see our diamond specialists in Perth today.