A Guide to Coloured Gemstones


From subtle sheens to bold and bright statements, we think coloured gemstones are amongst nature’s greatest beauties. With a rainbow of choice, the world is your oyster when it comes to finding the right hue for you. So from their geological origins to the history and lore surrounding each stone, here’s our run down of the most suitable coloured gemstones for fine jewellery and engagement rings.

Sapphire - Faithful & Serene

Whilst usually considered to be blue, sapphires can be found in a plethora of colours, from green to yellow, pink to purple, multi coloured and everything in between. A sapphire is a variety of corundum, and is essentially any corundum gemstone that isn’t red (these are rubies). Sapphires score 9 on the Mohs scale of hardness, only 1 ranking below diamonds, making them a suitable and popular alternative to diamonds.

Sapphires are symbols of truth, faithfulness and sincerity, and for hundreds of years have been associated with royalty and romance. Famously, Prince Charles proposed to Princess Diana with a striking blue sapphire, which became Kate Middleton’s upon her engagement to Prince William.

As per our modern-day associations with national treasures Princess Diana and the Duchess of Cambridge, blue sapphires are the perfect choice to for the giving, caring and loving person in your life.

Queensmith's  Classic Oberon  engagement ring, with 1.45ct natural blue sapphire

Queensmith's Classic Oberon engagement ring, with 1.45ct natural blue sapphire


Ruby - King of Precious Stones

Rubies are noted for their bright red, lustful tones. Many associate the colour red with love and passion, making rubies the perfect choice for engagement ring jewellery and tokens of love. As a variety of the mineral corundum, rubies are equal in hardness and durability to sapphires. Rubies were, however, given their own ident because of their unique allure and historical significance.

In ancient cultures, rubies were highly prized due to their similarity in colour to blood, with people believing the stones held the power of life. The Sanskrit word for ruby, ratnaraj, translates as ‘king of precious stones’, and in Ancient India, Hindus believed ruby offerings to the god Krishna would enable their rebirth as an emperor. Notions of wealth, health, wisdom and relationship success were adopted in medieval Europe, and today we still celebrate those symbolic associations of passion, love and desire.

As the GIA explain, ‘red is the colour of our most intense emotions - love and anger, passion and fury’. A deep red ruby is the perfect choice for a passionate partner.

A bespoke Queensmith design, featuring a pear ruby and halo of diamonds 

A bespoke Queensmith design, featuring a pear ruby and halo of diamonds 


Fancy Colour Diamonds - A Contemporary Classic

The geological conditions needed to produce a fancy coloured diamond are incredibly rare, making naturally fancy colour diamonds highly valuable. The deeper and more distinct tones are the most valuable, which can appear in blue, pink, yellow, green and brown hues. Naturally coloured diamonds are most frequently found in Indian, South African and Australian mines, before making their way into the world markets. With the highest score on the Mohs scale than any other stone, diamonds are the most ideal, as the well as the most traditional stone for engagement rings to last a lifetime.

In historic times, white diamonds were deemed the most attractive and popular of gemstones, but in recent decades the fancy colour diamond market has grown. Since, for example, brown stones adopted names such as ‘Champagne’ and ‘Cognac’ in the 1980s, awareness of coloured gemstones has soared.

New technologies have allowed for the colour of diamonds to be altered and enhanced. According to the GIA, treated diamonds aren’t common, but they test each stone they grade for the presence of treatments and will include the findings on the diamond’s certificate. By coating a diamond, the undesirable colour is masked with a super thin layer of chemicals or plastics of appropriate colour. Another method is high-pressure, high-temperature treatment, known as HPHT, which can enhance a diamond to be colourless, pink, blue, green, yellowish green or yellow, according to the GIA.

Due to the unique nature of fancy colour diamond hues, a fancy colour stone is a great choice for a contemporary and individual character. Learn more about the properties of diamonds and how to find your perfect stone here.

A bespoke Queensmith  trilogy ring  with two intense yellow diamonds and rubover setting

A bespoke Queensmith trilogy ring with two intense yellow diamonds and rubover setting


Emerald - A Symbol Of Growth

Green gemstones are in abundance, but emeralds are the most desirable due to rarity, value and durability. Having said this, emeralds are slightly less durable than diamonds, sapphires and rubies, reaching 7.5-8 on the Mohs scale of hardness. The stronger and deeper the colour of the emerald, the rarer and more valuable it is.

According to the Ancient Roman writer Pliny the Elder, the beauty of emeralds is restorative; ‘its soft, green colour comforting’, with abilities to remove weariness and lassitude. The first known emerald mines were located in Egypt, and the gemstone was a favourite of Cleopatra’s. European lore found future-telling powers within the green gemstone, which became popular when the Spanish brought the stone to the Western world form the South Americas.

As the birthstone of May, emeralds are associated with Spring and are a symbol of growth; a romantic choice for those excited for the future of their relationship and what's to come.

One of our emerald  engagement rings  being inspected before handing over to the client

One of our emerald engagement rings being inspected before handing over to the client


Whilst there are hundreds of different coloured gemstones on the market, not all would be suitable for fine jewellery. For engagement rings that are to be worn everyday, we would always recommend the stones that are the most durable, as well as the most beautiful. So whether you base your decision on aesthetics or the greater meaning behind your coloured stone, we’ll always be able to help you find the perfect gem for you. Diamonds, rubies, sapphires and emeralds - which is your pick of the bunch?