The Four C's of a Diamond copy


To understand the magic of the diamond it is essential to understand the measures we use to decipher this wondrous object, and at Stefan our specialists are expert at helping you understand the cut, clarity, colour, and carat weight, the quintessential 4 C’s of diamonds.


Fire and brilliance, dark and light – the exquisite wielding of the diamond cutters art.

A perfectly cut diamond sparkles with intensity and fire. The ‘Cut’ refers to the proportions and extraordinary finish created when transforming a rough diamond into a finely polished diamond.

Of all the four Cs, ‘cut’ has the most influence on a diamond’s brilliance, radiance and beauty. Round diamonds, with the most demanding cutting standards, are the most brilliant of all shapes.

To measure the exacting proportions of a Stefan diamond, our diamond cutters and buyers use the ‘Sarin Brilliant Eye’. A complex machine, able to carefully and consistently measure every facet and angle, providing unparalleled accuracy and a detailed printout of the quality and precision of a round diamond’s cut.

Each round diamond receives a Sarin cut grade from 0, being the most brilliant, to 10, the least brilliant. This extra step is just one way Stefan Jewellers take the mystery out of evaluating and comparing stones, assuring that you are getting the most beautiful diamond for your budget.

When a diamond has been cut to ‘ideal proportions’ by a master cutter, it will refract light internally from one facet to another, and release the light through the top. This creates the enchanting sparkle and brilliance that make Stefan diamonds so exquisitely desirable.

To achieve this every diamond bearing the Stefan name is cut either ideally (0) or premium (1-2) cut. We won’t sell any stones that we deem cut too shallow or too deep, or recommend a round brilliant cut diamond with a Sarin grade’ above 4.


It’s remarkable that a characteristic so subtle can have such a dramatic impact on a diamond’s value. However, truly colourless diamonds are the most rare and exquisite of them all.

To the untrained eye, most gem-quality diamonds appear colourless, when in fact there are minuscule differences in shade – the result of trace elements combining with carbon over the diamond’s million-year formation.

To determine its true colour, every Stefan diamond is graded in an accredited, internationally recognized Gemmological laboratory. It is viewed on its side under balanced white light and assigned a colour grade according to an internationally recognised “Master Set” of diamond colour grades.

Thanks to this unique certification, you can have absolute ‘confidence’ that your Stefan diamond reflects all the subtle, colourless beauty you have fallen in love with.


All diamonds are unique. And while all Stefan diamonds are incredibly beautiful, no two are alike.

It’s a fact that most diamonds have flaws, called ‘inclusions’. These inclusions form an integral part of the personality unique to each diamond. Inclusions can be in the shape of crystals, feathers or lines generally unseen to the human eye unless magnified.

Clarity is determined by the absence of inclusions – the fewer the inclusions, the more rare and more valuable the diamond. Clarity ‘grades’ are then determined by the number, size, colour and location of inclusions. The smaller and less visible the inclusions, the higher the diamond’s grade.

Stefan diamond graders and buyers use a type of microscope called a ‘Gemscope’ for examining diamonds. This allows inclusions to be easily seen and evaluated, so when you choose your Stefan diamond, you can do so with absolute ‘confidence’.

When selecting your diamond in store we are happy to provide a Gemscope for you to use, so you can discover the unique qualities that make your diamond beautiful and unique.


The most obvious factor of a diamond’s value is its size. However, two diamonds of equal size can have completely different values because of the other Cs: cut, colour and clarity.

As with all precious gems, the weight or size of a diamond is measured in carats. One carat is equal to 200 milligrams. When weighing diamonds, a 1.00 carat is divided into 100 points; therefore, a diamond of 25 points is also described as 0.25 carats or a quarter of a carat.

As a diamond increases in size, its rarity increases, which also increases the price-per-carat exponentially. Therefore, a two-carat diamond is more than twice as valuable than a one-carat diamond of the same quality and characteristics.

At Stefan’s we like to add a 5th “C”, which stands for “Confidence” in the quality of the diamonds that we sell. This is our passion!