Find out how pink diamonds are formed and what makes them rare.
Relatively unknown until a steady supply came to the world’s notice in the 1980’s, the first question that comes to mind about the rising accessibility to pink diamonds is their authenticity. After all, the most popular diamond is a clear, beautifully cut form. Yet many ‘colourless’ diamonds are not transparent due to the presence of a degree of nitrogen. Its counterpart, the industrial diamond is inferior so the purity, or clarity of the diamond itself must increase not only its beauty but its value too.
Now pink diamonds share the spotlight with their darker red counterparts to rank highest among some of the most valuable diamonds in the world. Unearthed less frequently than other coloured diamonds, their colour ranges from the softest strawberry juice to the richest crimson of a plum skin, but there’s still one question that’s very typical: is a pink diamond natural?
The answer is a resounding, YES. All coloured diamonds are a rarity. Pinks, reds, blues and violets are some of the hardest to find diamonds due to their unique creation. So, how do these beautiful stones come to life? Read on and find out.
Naturally coloured diamonds
Coloured diamonds have been admired throughout history, mined across the world and found in a range of colours. There are gorgeous blue, violet, yellow, green and grey diamonds with shades in between. The most famously known blue diamond is the Hope diamond. In 2019, Graff Diamonds purchased the Firebird, a 20.69 carat yellow mined from the Alrosa, Russia. Three years before Brazil delivered the Aurora Green, an astonishing 5.03 carat green diamond without fluorescence.
Pink diamonds have been found in various parts of the world. Mined in Brazil, Russia, Canada, Tanzania, and South Africa, the uniquest of all pink coloured diamonds are from the Argyle mine in Kimberley, Western Australia. Specific conditions in this area have resulted in a pink diamond distinctive to those mined elsewhere.
How do natural diamonds form?
To understand how pink diamonds form naturally, we need a refresher course on how any diamond forms. By knowing how a regular diamond forms, we will understand how different coloured diamonds form.
Diamond formation is an extensive process which happens deep beneath the earth’s surface. The most common conditions for diamond formation are underground depth, heat and carbon material. This carbon material needs to be at least 160 km underground and subjected to temperatures around 1150°C to become a diamond With these conditions met, carbon atoms bond together to create a crystal lattice structure. The carbon atoms found in a standard, colourless diamond are arranged in a traditional cube-like arrangement. The lattice structure of a perfect colourless diamond has no deformities and only uses carbon atoms.
Realistically though, diamonds are impelled from the depths by volcanic activity as pressured magma creates a pipeline to the surface. During this journey any number of events change the final characteristics of a diamond, typically nitrogen and other impurities are found trapped inside natural diamonds. It is exceptional that a diamond survives without being converted to graphite or resorbed before erosion deposits it within a human’s reach.
How do natural pink diamonds form?
Now that we know how diamonds form, what makes a pink diamond so unique?
Colours in most diamonds can be divided into either impurities trapped within or significant deformation of the carbon crystalline structure.
During their formation most coloured diamonds absorb trace elements or radiation, which affects how light wavelengths are absorbed and reflected through the crystalline lattice. Blue and yellow diamonds are examples of contamination by trace elements. Green diamonds are affected by radiation.
Occasionally diamonds come from deeper in the Earth. Blue diamonds, for example, develop at a depth of at least 650 km below the earth’s surface. These have trace amounts of the brittle metalloid – boron. The bonding of boron and carbon during the formation results with a diamond that absorbs red, green and yellow wavelengths of light allowing blue to pass through. A deeper blue is the result of high concentrations of boron being present when the carbon atoms began transforming.
Yellow diamonds have trapped large amounts of nitrogen in them. During formation nitrogen replaced some carbon in the lattice. This substitution results in blue wavelengths being absorbed, leaving an readily observable yellow.
While trace elements are the reason for the appearance of most coloured diamonds, they do not cause pink diamonds, but they may create a secondary colour effect such as a purple or brown undertone in the gem.
Due to the conditions in the region at the time the crystal was forged, a pink diamond is formed differently. At the time these diamonds were forming pressure and temperature became so extreme it caused the carbon crystallising structure to distort. The layers of the lattice slipped leaving parallel bands called high pressure graining. Light refraction through these bands is the apparent cause of a pink, or a red diamond’s colour and, typical for gem quality stones from the Argyle mine, the tighter the graining planes are, the more vibrant the colour. Non-Argyle diamonds do not have the same degree of distinctive graining and are less intensely coloured.
Pink diamonds are romantic and enduring. They are among the most valuable in the world and can be worthwhile investments. If you’re looking for something to put your money on, pink diamonds are worth it.
Argyle pink diamonds are the scarcest in the world. Many people are looking to add these one-of-a-kind diamonds in their collection. Thus, it’s best to invest in a pink diamond today and watch your money grow. The world loves pink diamonds, and we’re sure you’d love them too.