Gemfields explains the all-important 6 Cs and offers the ultimate guide to buying coloured gemstones.

When it comes to buying coloured gemstones, there are a host of factors to consider – and not all of them are obvious.

Some of these relate to aesthetics, while others are about ensuring the provenance of the gem, but all are equally significant.


The complexity of the gemstone buying process, in many ways, mirrors the miraculous set of circumstances that was required for these extraordinary quirks of nature to form.

Ascribed mystical qualities since ancient times, emeralds and rubies are no ordinary purchase: they are lasting, and so it is important to pore over every detail before deciding on ‘The One’.

Take time to fall in love…

Far and away the most important rule of buying is for the prospective buyer to – quite literally – choose the gemstone that they fall in love with, rather than opting for the one they think they should like.

This may be a less ‘perfect’ gemstone – and, in fact, its little quirks may be the very thing that makes the buyer fall for it.

Inclusions keep it real…

Perfection is in the eye of the beholder when it comes to gemstones, which were carved from Mother Nature and formed deep beneath the earth’s surface millions of years ago.

Inclusions – as they are called in the industry – are the little features that prove that a gemstone is authentic, and that no two are exactly the same.

These are to be celebrated.

Opt for an even colour…

What is worth insisting upon when shopping for a coloured gemstone is evenness of colour and good saturation throughout the gemstone.

This is typically associated with a higher value, higher quality gem (unless it came about as the result of colour enhancement).

View gemstones in daylight…

The importance of seeing clearly when it comes to choosing a gemstone cannot be underestimated.

When shopping for an emerald or ruby, a buyer would be best advised to try to see it in daylight, so that its colour is not affected by artificial light.

6 Cs to remember…

Colourless diamonds have long been measured by the 4 Cs – colour, cut, clarity and carat – and there are two more added to the mix for coloured gemstones: character and certification.

These 6 Cs are as good a guide as there is to making an informed decision – and also a snappy way to remember the basic rules of the game!

Trust the brand…

Gemstones should always be purchased from a trusted supplier – someone who is known or has come through a personal recommendation perhaps.

This will give the buyer peace of mind that their gemstone has been responsibly sourced and is of the quality described.

Get it in writing…

Especially if a gemstone is of a significant size, it is important to request a lab report – verifying its origins and disclosing any treatments it may have received – from a certified gemmological laboratory, something that all reputable labs will be happy to provide.

Traceability records provide a complete picture of the journey a gemstone has travelled to reach its final destination (in a beautiful piece of jewellery).

Do your homework…

It is important to ask questions and do research when finding a gemstone to buy.

Responsible sourcing and sustainability are hot topics today, and jewellery brands, many with their own in-house gemmologist teams, will be able to supply plenty of information.

There are many credible sources – like jewellery experts, gemmological labs and industry bodies – on hand to answer questions.

Know your gem’s journey…

Every gemstone is a tiny miracle and completely unique in terms of its character and the journey it has taken. It’s often said the right gem will find its owner.

Buyers who follow this advice and do their homework will certainly help the process along.


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