10% OFF YOUR NEXT PURCHASE

Coloured Diamonds: Beauty Crafted in Nature

May 19, 2020

Coloured diamonds

Looking at the process of coloured diamonds forming naturally, as well as the differences in environments which create the beautiful range of colours we see in today’s jewellery.

How are Coloured Diamonds Formed?

I was recently posed a question about how coloured diamonds are formed; since it’s quite a complex (and slightly scientific) subject, I’ve tried to keep this post as short and concise as possible and cover the basics of how each coloured diamond is formed.

As many people already know diamonds are made predominantly from carbon. They grow around 90-100 miles below the earth’s surface where the carbon molecules are placed under extremely high temperatures and pressures. The crystals are then brought to the surface during volcanic eruptions and subsequently mined or found loose. 

Most diamonds and diamond jewellery are colourless exhibiting little or no colouring. However, there are occasions where secondary geological, elemental or radiation based factors affect the final gemstone that will be cut from the rough stone. 

It is these growth-based variations which will ultimately decide the nature of the diamond, as well as the colouring that it will exhibit. Below are a selection of diamond colours and an explanation as to why that colour has developed.

Natural Brown and Champagne Diamonds

Chocolate Brown Diamond

This colour group includes stones that are usually referred to as chocolate, cognac, lightly tinted brown or champagne, these variations reflect the darkness of the stone. Colouring results from a structural distortion within the crystal which changes the way that light is absorbed by the diamond.

Natural Pink Diamonds

Pink Star Diamond

Pure pink diamonds are a real rarity and usually found in much smaller sizes and are one of the most desirable stones. Whilst many pink stones will exhibit secondary hues, the colouring is the result of tremendous pressure creating distortion to the atomic structure of the stone and graining.

Natural Red Diamonds

Fancy Apple Red Diamond

The rarest of all the coloured diamonds, very few have ever been graded as fancy red. The red colouring is the result of deformation to the atomic lattice of the stone, and can be found with brownish, pinkish and purplish colourings.

Natural Blue Diamonds

Hope blue diamond

Blue diamonds are typically described as blue, greyish blue, greenish blue, turquoise and aquamarine. The colouring of the stone is caused by the presence of Boron within the diamond structure. The greater the concentration the stronger the colour. 

In the case of turquoise or aquamarine coloured stones the colouring is the result of long exposure to radiation during growth. Argyle blue stones which have a greyish blue hue owe their colouring to hydrogen and in some rare cases nitrogen within the crystal structure.

Natural Green Diamonds

Green Diamond

The second rarest of all the natural diamond colours, green diamonds result from the crystal being exposed to naturally occurring radiation for a period of millions of years. Green diamonds that offer no secondary colouring and have exceptional intensity and purity of colour are extremely valuable. 

 

Natural Olive Diamonds

A distinct colouring within its own right olive coloured diamonds aren’t part of the green family. The colouring is usually caused by the presence of hydrogen impurities and secondary colourings can include grey, brown and yellow.

Natural Orange Diamonds

Fancy Orange Diamond

A difficult colouring to classify due to the primary colours of red and yellow being key in the creation of orange. The colouring itself is thought to result from a deformity in the crystal structure and the presence of nitrogen.

Natural Chameleon Diamonds

Chameleon diamonds change colour depending on lighting or temperature and are considered collectors items. Colour changes range from orange to olive and yellow to olive. This colour changing characteristic is believed to be due to a greater than normal level of hydrogen impurities.

Natural Grey Diamonds

Offering an amazing range of colour variations grey diamonds are not too far removed from colourless stones and include colourings such as greyish blue, greyish yellow, greyish green and so on. Extremely rare and highly sought after, the colouring results from the presence of hydrogen and little or no nitrogen, except for greyish blue stones which are likely to result from boron.

Natural White Diamonds

Fancy White Diamond

Not to be confused with the more commercially available colourless and transparent diamond these stones have a snowy colouring to them. Sometimes referred to as being opalescent the colouring may result from the presence of nitrogen and sub-microscopic inclusions that scatter the light.

Natural Purple Diamonds

Grey violet diamond

Another colouring that is extremely difficult to classify due to the secondary colourings it can be found with, many are described as pinkish purple. The colouring in these diamonds results from internal, structural characteristics.

 

 

Which Diamond Colour is your Favourite?

With a range of naturally-formed and beautiful coloured diamonds to choose from, picking your perfect diamond colour can be a tough decision and while it all comes down to personal preference, I hope this backstory on how each coloured diamond is formed helps inspire you to find your favourite colour.


Thanks again to the person who sent this question in and get in touch if you have any other queries relating to diamonds, jewellery or gemstones. Check out our specialist guide to picking your perfect diamond or take a look at some of the stunning diamond jewellery at Charles Nobel.

Customer reviews

T
Tamsin Beken

I highly recommend Charles Nobel and their lovely staff. They have done a brilliant job resizing my wedding ring, which is made up of three different types of gold so not an easy task. They were really helpful, professional and honest in their advice. Thank you!!

Read more
J
Julie McStraw

I had a ring redesigned into a more modern pendant. Piers understood how I imagined the design to look - modern and unique. We spent a long time deciding on the best of the designs that were produced to fit my brief and I am extremely pleased with the finished product. I wouldn't hesitate to recommend this service

Read more
A
Ali Geake

Absolutely fabulous customer service and beautiful earrings for my goddaughter. Thank you to Piers and Emma who offered such helpful advice and even a gift wrapping service for a last-minute present for my goddaughter. She was thrilled - and so was I! Highly recommend such a personal touch when jewellery shopping.

Read more
S
Stephanie Kosandiak

My antique engagement diamond solitaire ring (which I had worn for 41 years), was in need of a new shank. At the same time I was advised to renew the setting. I was concerned that a new setting would change the character of the ring. I couldn’t have been more wrong!! The ring looks fabulous. The setting has improved the appearance of my diamond enormously and I have to admit I was quite emotional when I saw the result of the “repair “. I now have a beautiful new ring which has maintained its character but has been brought up to date. Thank you too to the Charles Nobel staff for their advice and craftsmanship! I am a very satisfied customer!

Read more

Sign up to our newsletter to receive an exclusive 10% off your first online order*

× How can I help you? Available from 09:00 to 17:30