Diamonds 101. Your Basic Guide To Diamonds

Diamonds are a classic stone that adorn many types of jewellery, from pendants to the all-important engagement ring. Buying a diamond can be intimidating, so it helps to arm yourself with some basic knowledge before you shop.

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Diamonds are judged based on five characteristics, commonly known as the 5 Cs: Cut, Colour, Clarity, Carat and Certificate. If you follow the 5 Cs when shopping for a diamond, you can’t go wrong.


Cut is the only characteristic of a diamond not influenced by nature. As such, the cut can feature the mistakes caused by incorrect practices, so it’s important to understand this aspect more than anything.

"If a diamond is cut incorrectly, the defining sparkle will be compromised."

It is how the 57 or 58 facets (the tiny planes cut on the diamond's surface) are angled and sized that dictate how light reflects and exits the diamond, an effect known as its "fire". Make the cuts too deep or too shallow and the diamond will be less brilliant. Triple Excellent, or "EX EX EX" is the best grade cut in a diamond.

Diamond and Gemstone Cuts

The cut will also determine the shape of the diamond. The most common shape is the round cut, but others include the emerald, the pear, the marquise, the princess, the oval and the heart shape. Each shape creates a different feeling. For example, a heart shaped diamond is very romantic and feminine, while a princess cut is very sleek and modern. Ask to see all of these shapes, if only in a picture, to make sure you have covered all your options.

The most valuable and rare colour is white, that is to say, colourless. Jewellers grade absolutely colourless diamonds with a "D". The scale moves down from “D” to "Z" and, between these two extremes, diamonds will display subtle coloured tones. Diamonds with a very strong and distinct colour, or “fancies”, are extremely rare, like pink and blue diamonds.

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"D”, “E”, and “F” are all colourless diamonds.
"G" "H" "I" "J" are called nearly colourless, and display a slightly yellow tone
"K" "L" "M" are faint colour 
“N” through “R” are very light colour
“S” through “Z” are light colour

The further down the scale you go, the more common, and thus the more affordable, a diamond is. If you are after a good quality diamond keep to colourless or nearly colourless grades.


Many people get unnecessarily hung up over the clarity of a diamond. Look into most diamonds with a magnifying eyeglass and you will see small "inclusions", also known as "nature's fingerprints". They look like small clouds or feathers, but are usually invisible to the naked eye.

"Inclusions can affect the diamond's fire, but they also make your diamond unique and shouldn't always be seen as a fault." 

Just like colour, clarity has a measuring scale. As long as the stone is graded SI1, Slightly Included 1, or better, your stone will look perfect to the naked eye. The scale starts at the high end with IF, or Internally Flawlessly; VVSI1 and VVSI1 for Very Very Slightly Included; VSI1 and VSI1 for Very Slightly Included; SI1 and SI2 or Slight Included; I1 and goes to I3, for Included. 


Carat and Certificate  

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Rings above feature our Athena Ethical Diamond Platinum Engagement Ring (also available in 18ct Fairtrade Gold) click to view

The weight, and thus the size, of a diamond is measured by carat. A carat is equal to 0.2gm, or 200mgm. A carat is divided into 100 smaller units called points. For example, three-quarters of a carat is 75 points. The average size of most engagement ring diamonds is somewhere between one carat and 0.3 carat. Do not confuse carats with karats, the unit of purity for gold.
The Certificate will tell you which laboratory has certified the 4C's of the diamond and in some cases it will also tell you the provenance of it. For example if your diamond comes from Canada, the certificate will feature a little maple leaf and an identification number inscribed on the stone to ensure your stone is fully traceable. The most recognised laboratory in the jewellery world is the Gemological institute of America (GIA) and HRC in Europe.

With these 5 Cs, you’ll be able to pick out a great diamond that is perfect for the occasion:


  1. Carat:           0.3ct-1ct

  2. Cut:              Triple Excellent, or "EX EX EX" 

  3. Clarity:         SI1, or better (VS1-VS2)

  4. Colour:         "D”, “E”, and “F”  

  5. Certificate:   GIA & Canada Mark


Most of our Engagement Rings come with a Canada Mark certified diamond, so if you want a fully traceable and ethical diamond to celebrate your love, come and check our designs.

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Love, Arabel

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