Engagement Ring Buying Guide


Although nowadays 75% of engagement rings are diamond solitaires, this has not always been the case and coloured stones are starting to make a comeback.  In fact, this myth resulted from a clever marketing ploy by De Beers, the world’s largest diamond company.  Diamond is the hardest natural substance on earth; only a diamond can scratch another diamond.  BUT this is not to say they are indestructible.

If you have been researching engagement rings, you will have been bombarded with the Four C’s - cut, colour, clarity and carat.  


Often the least considered factor, the CUT of a diamond is probably the most important of all.  If a diamond is cut incorrectly, its sparkle will be compromised.  The cut dictates how the facets are angled and sized which will affect how much light is reflected back out of the stone.  If cut badly, the proportions of a diamond can result in the stone appearing dull.


Ideally, diamonds should be without colour.  The most valuable colour is graded as a "D" and is considered “colourless”.  As colour increases, the grades move up the alphabet.  (A,B and C have not been used to date).  Although people can get really preoccupied with the colour grade, the tonal differences are so subtle that it is very unlikely that an untrained eye can detect the differences of diamonds graded up to I. 

Fancy-coloured diamonds with a very strong colour are extremely rare and graded separately.


As a natural substance, virtually all diamonds will have small imperfections known as inclusions.  Clarity is the measure of how easily these inclusions can be seen.  


Some of the lower grades may exhibit inclusions which are only just visible to the naked eye, while inclusions of the higher grades will only be seen under a jeweller’s loupe.  Some consider the inclusions as just part of a natural product and representative of a diamond’s individual character. 


Diamonds are measured by weight not size.  A carat is divided into 100 smaller units called points. For example, three-quarters of a carat is 75 points. Don’t confuse this with carats - the measure of precious metals.

Like normal carrots, diamonds are priced by weight.  However, unlike carrots, diamond carat price varies depending on how big it is.  When a rough stone is cut, any wastage is cut into smaller and smaller diamonds.  Consequently, the larger diamonds are much rarer and will rise in price.  So buying three 25 pt diamonds will be more affordable than choosing one 75pt diamond.

It is also worth considering that there are popular weights that customers will pursue eg. the 1ct solitaire diamond ring.  However, if you drop down to 90pts, the price per carat will be less and you really can’t tell the difference with the naked eye.


While many brides may have a definite preference as to the diamond shape, you should be aware that not all shapes are equally sparkly.  Both the number of facets and the way they bounce light around the inside of the stone will determine how much light is reflected back out.  More light equals more sparkle.

The most popular shape is the round brilliant cut.  It has either 57 or 58 facets and the symmetry of the shape results in lots of light being reflected out; which is why this shape is the most sparkly. 

The princess cut diamond generally appears as a square although it may be slightly rectangular.  While it usually has approximately 76 facets, slightly less light exits the stone, so it is not as sparkly as the brilliant.  Its price per carat will be slightly cheaper than a brilliant because there is less wastage when cut from a rough diamond.

Other fancy cut diamonds are popular with designers always in search of new and exciting contemporary twists to the traditional engagement ring.  While these offer more options in terms of design, these will vary in terms of the light reflected,  


This is your decision and you need to pay what you feel is appropriate and affordable.  Don’t be afraid to tell us what price point we need to work to; because there are so many different elements involved in the process, we can adapt the specification to achieve the perfect engagement ring for your budget.


Larger diamonds are sometimes sold with a certificate issued by an independent, certified laboratory.  This is actually a report of its characteristics and authenticity, not its monetary value.  The report should contain information about the clarity and colour grades, plus the shape, weight and measurements of the diamond and a brief assessment of the quality of cut and finish.  They will also plot any inclusions and imperfections in your diamond onto a diagram together with any identifying laser inscriptions. 

There are several different diamond grading laboratories and some are stricter than others.  The most well-known and well-regarded laboratory is the GIA – Gemological Institute of America.   We also supply stones with certificates from IGI – The International Gemological Institute and EGL – European Gemological Laboratory.

Be aware that some diamond jewellery brands offer their own ‘certificates’ or diamond ‘guarantees’ but these are not independent from the retailer.

Click here to shop the latest Engagement Rings from Lance James.