Aside from their exquisite beauty and everlasting charm, coloured diamonds have been cherished throughout history, and used to create some of the most esteemed jewels. From ruby red rings to emerald-encrusted crowns, coloured diamonds come in a wide selection of tones and styles, made up of hues and shapes for advanced rarity and attraction.
What are the rarest coloured diamonds?
There are a small number of diamond mines across the globe that are recognised for the unique diamond colours they manage to produce, leaving craftsmen and enthusiasts with a selection of rare coloured diamonds. Amongst these findings are only 12 coloured diamonds, made up of 9 intensity levels, 90 secondary hues and over 230 colour combinations.
While all diamonds are unique in their own way, particular forms are especially uncommon, known as rare-coloured diamonds.
Red diamonds are the rarest of the coloured diamonds, with only 20-30 existing across the world. The rich red tone is achieved by a unique process during their formation, which changes the crystal structure of the diamond and causes light to pass through it, something which doesn’t occur during the formation of a colourless diamond.
Fancy reds come in a variety of shades ranging from orange-red to a more brownish undertone.
Resembling a sense of romance and femininity, pink diamonds are rare yet highly popular. While intense fancy pinks are extremely rare, a faint pink diamond is slightly more accessible.
One factor which contributes to their rarity is that the cause of their colour remains unknown. Pink diamonds are made of pure carbon, similar to colourless diamonds, but are composed of a different crystal structure to reflect the dazzling pink finish. These stones are also mostly mined by one single mine the Argyle in Australia.
Discover our selection of Pink Diamond Jewellery
With many diamond experts stating Blue is the second rarest diamond, these stones are adorned all over the world for their limited accessibility and striking finish.
There are only a few mines in the world that will mine blue diamonds, located in South Africa, Australia, and India, comprising only 1% of all the mined coloured diamonds worldwide. These stones are often associated with royalty, passion and hope.
Fancy green diamonds are also one of the top products when it comes to rarity. Due to the volume of artificial enhancements, finding the natural state of these diamonds is key to determining their value and if natural, is considered a true beauty in the diamond industry.
The rarest types of diamonds
When looking at diamonds, their colour and type are two different things. In terms of formations, type IIa is the rarest form of diamond followed by the type Ib.
The Type IIa diamond possesses only 1% of all the world diamonds, also named “Golconda Diamonds” after the famous Golconda mine in India. Made up of no nitrogen impurities and finished in a colourless state, this type of diamond is considered to be the most chemically pure and has also crafted some of the world’s most opulent diamonds such as the one used in the British crown.
TYPE IB AND IIB
Allegedly less than 0.1% of natural diamonds are Type Ib. These diamonds are typically intensely coloured, presented in yellow, brown and orange hues. An IIb diamond is also extremely rare and usually has a blue tinge. Known to conduct electricity, these diamonds are highly valuable.
How are rare-coloured diamonds formed?
Most naturally-coloured diamonds are formed when trace elements combine with the carbon atoms during the diamond’s creation. The existence of chemical elements such as nitrogen, sulphur, and boron can colour diamonds in shades of yellow, green and blue.
Depending on the colour of the diamond and its rarity the process can change slightly, although the mining and extraction are the same. Here are some simple explanations of how the rarest diamonds are formed.
- Blue: The colour blue comes from the chemical element boron trapped inside the diamond during the formation process.
- Green: A natural green diamond does not develop until the end of its journey to the earth’s surface. Absorbing red and yellow light causes the diamond to reflect a green hue which is usually confined to a very thin layer at the surface.
- Pink: The origin of pink colouration in natural diamonds still has many unanswered questions. Experts believe that pink diamond shades are caused by plastic deformation, in response to extreme natural stresses.
- Red: Although still sceptical, scientists believe that red diamonds get their colour in a similar way to pink diamonds due to plastic deformation.
Rare-coloured diamonds handcrafted by David Morris
For 60 years the House of David Morris has used rare coloured diamonds offering an incredible range of coloured diamonds, be it yellow, pink diamonds, blue diamonds, green diamonds or rarest-of-the-rare red diamonds.
All the rare coloured diamonds used in David Morris collections are GIA certified, affording the buyer complete peace of mind and transparency. The astonishing colour spectrum of rare coloured diamonds makes them amongst the world’s most sought-after. Within this exceptional family of diamonds, a shade to suit every style and personality can be found, whether that be in a ring, a bangle or a pair of earrings.