It's the cut that makes the difference

The 4c's of diamond grading



Diamonds are measured by weight, the unit of scale is referred to as carat abbreviated ‘Ct’. One carat is equal to one fifth of a gram, and is based on the weight of a carob bean from ancient Egypt. Each carat is then divided into 100 points.

Within the industry, diamonds are also sold as units per carat. That is, if there are 10 diamonds each 10 points in weight, then they weigh in total one carat. Hence they are known as 10 per carat or 10 points. A 0.01ct is also known as a 100 per carat or 1 point, and 0.02ct is a 50 per carat or 2 points.

The price of diamonds is based upon rarity; larger stones are rarer than smaller stones.

This means that the larger the stone the higher the price per carat.  A one-carat stone is much rarer than two half-carat stones, and is therefore generally more than twice as expensive.

It has been suggested that it takes approximately 80 tons of ore to find a crystal large enough to cut a 1ct plus diamond.



Many people consider all diamonds to be colourless. In fact, diamonds come in every colour of the rainbow, as well as Black! Moreover, they come in varying degrees of intensity of each and every colour.

The most sought after diamonds are those that have no colour. It is this lack of colour that makes these diamonds the most valuable.

Eternity Diamonds are available in colours D through to I.  The finest colour is known as ‘D’ colour, and as other colours taint this pure whiteness, the colour grade of a diamond is decreased. The following table outlines the colour grading scales used within the Australian and New Zealand industry.

From ‘D’ to ‘I’ the stones appear white to whitish. The subtle white tone change is very slight and can be compared to the different tones of white paper you may have on your desk.  As we proceed down the list you will notice that either yellow or brown can taint the whiteness of diamonds.

It is critical that the colour grade be correct!  Diamond colour is determined via a visual assessment and/or with the aid of an electronic colour-grading machine.  Visual assessment is undertaken using a known set of master stones to compare against.

In addition to the visual process Eternity Finely Cut Diamonds are also graded on an electronic colour-grading machine that ‘reads’ the diamond colour and prints the grade onto a card. Since the human eye is not as accurate as the machine, the grade is printed as a bar onto the report card, indicating the natural variance that the eye would not detect.



Eternity Finely Cut Diamonds are graded to internationally recognised standards, and are cross-checked by at least 3 qualified diamond graders. These three separate graders must agree on the final clarity and examine every Eternity Diamond.  This is your assurance that you are getting exactly what is specified. 

The most popular clarity of diamonds for Eternity Diamonds engagement rings is between VS1 and SI2.  In these grades, imperfections cannot be seen with the unaided eye and are still at a price that is deemed affordable by consumers at large. 

Clarity refers to the level of inclusions, in other words the degree of natural imperfections a diamond possesses.  Few things in nature are absolutely perfect and diamonds are no exception. Diamonds may have internal inclusions or external blemishes that are often referred to as natures fingerprint.   

These inclusions can affect the brilliance of a diamond as they may interfere with the refraction of light within the stone.  The fewer inclusions, the rarer and more valuable the diamond.  Diamonds are clarity graded under a special fully corrected triplet x10 magnifying loupe. However, further examination of very clean stones is done under a binocular microscope. 



Cut more than any other of the 4C’s will give Eternity Diamonds the sparkle and scintillation that you are looking for.  At Eternity Diamonds cut is our niche- and we pride ourselves on producing the highest quality cut diamonds.

The sad truth is that many diamonds today are not cut as well as they could be. Many cutters choose to sacrifice some of the diamond’s beauty and fire to achieve a stone that is either a higher carat weight or a larger diameter.  We do not adopt this approach at Eternity Diamonds and will always choose a beautiful stone over a large unappealing stone. 

Cut, more than any other characteristic, gives the diamond its sparkle.

As you can see above, when all the angles are correct, the light that enters is dispersed back through the diamond’s top facets. When a stone is cut too shallow or too deep, the light that enters through the top is allowed to escape through the bottom and does not allow the maximum beauty of the diamond to be realised.



Hearts and Arrows are not for everyone. They are for the individual that seeks the best in everything and won’t settle for second best. True Hearts & Arrows are rare and limited in production; so only select jewellers can offer them. You can own a masterpiece that is extraordinary in brilliance and sparkle like none other. No ordinary diamond can match the fire it will light in a woman’s heart.

Hearts and Arrows Diamonds are cut to ideal proportions with superior optical symmetry and a specific faceting pattern. When all these factors are in harmony the result is a repeatable, near perfect pattern of eight symmetrical arrows in the face up position, and eight symmetrical hearts when viewed in the table down position.