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Diamond Buying Guide

A simple guide for what you need to know when buying diamonds. Our diamond buying guide will give you the knowledge and confidence needed to buy diamonds of an exceptional standard. Diamonds are prized for their unique properties and characteristics, including exceptional hardness, high lustre, fire and brilliance.

Whether you are searching for the perfect diamond engagement ring, diamond set wedding ring, eternity ring, diamond earrings, diamond necklace or diamond set bracelet, we have an experienced team of diamond specialists, to help advise you on selecting the finest quality diamond jewellery.

4 Cs of Diamonds

The four characteristics which are considered the most important in determining a diamonds overall quality and value are:

  • Cut
  • Colour
  • Clarity
  • Carat Weight

The 4 C's are incredibly important when it comes to making the final decision on which diamond is right for you. The overall cut, colour, clarity and carat weight, affects a diamonds perceived quality and value, and therefore each is a significant factor to consider when purchasing a diamond.

It is recommended that you research how each of these key factors impact and influence the overall appearance and value of a diamond. We carefully grade and assess each individual diamond on the 4 C's using an international grading scale. 

Selecting a diamond is often a compromise - we would always recommend to concede on size (carat weight) over quality, to ensure you get the very best for your budget. This is because cut, colour and clarity are all key factors that will impact directly on a diamond's visual qualities.

Speak with our experienced team of diamond experts, who are happy to provide advice and assist you in finding the perfect balance between the 4 C's when choosing a diamond.


Cut is one of the most important factors when assessing the overall appearance of a diamond. A diamonds cut relates to the overall shape of the diamond when cut and faceted. The fire and brilliance of a diamond depends heavily on its cut and may be affected by the shape of the stone.

Round brilliant cut diamonds are recognised as the most popular diamond shape, considered as the ideal cut for a diamond. Alternative diamond cuts include princess cut, emerald cut, radiant cut, asscher cut, oval cut, pear cut, marquise cut and heart cut diamonds.

Cut also relates to the proportions, symmetry and polish of a stone, which is also taken into consideration when assessing, grading and certifying a diamond. 


Colourless diamonds are the most desirable and highly prized, since they allow the most refraction of light which visibly improves the overall brightness and sparkle of the diamond. Diamonds which draw colour or show any saturation of colour absorb light, which inhibits a diamond's brilliance. Coloured diamonds are graded differently, and are measured on their individual brightness and colour intensity.


Most diamonds contain their own unique characteristics which may be classed as inner flaws, surface blemishes, inclusions, and internal imperfections that naturally occur during the formation process. Flawless or internally flawless diamonds are often more highly prized, and priced. Each diamond is carefully assessed and individually graded based on the visibility, number and size of these inclusions, which determine the overall clarity of a diamond.

Carat Weight

A carat is the unit of weight by which a diamond is measured. Larger diamonds are often considered as rarer, and therefore often command a higher value. It is very important to understand how factors such as cut, colour, and clarity affect the overall value of a diamond. 1.00ct = 0.2 gram.

Diamond Certificates

A diamond certificate or grading report is a great way to understand the unique characteristics of a diamond, whilst offering reassurance of the true quality of a diamond. We only work with trusted international diamond laboratories, including the GIA, HRD, IGI, carrying out diamond reports by a qualified professionals. Each diamond is carefully assessed and graded using an international diamond grading scale, issued with its own individual report number.

British Diamond Company, The UK's Leading Diamond Jewellery Specialists

Discover the finest selection of elegant diamond engagement rings, diamond set wedding rings, eternity rings, diamond earrings, diamond necklaces and diamond set bracelets, available with an incredible choice of diamond cuts.

Contact our dedicated team of diamond specialists on 01335 453 453 or email, for help and advice selecting the perfect piece of diamond jewellery. Find a beautiful selection of ethically sourced diamond rings and jewellery available to order today with 0% interest free finance and free delivery.