While many of the basics of how to buy a diamond apply to all diamond types, they vary a bit among the different colours. Such is the case with natural pink diamonds, which are among the rarest and expensive in the family of fancy colour diamonds. Let’s take a look and find out which factors to consider to make a good investment.
What Are Pink Diamonds?
Natural pink diamonds are among the rarest of the fancy colour diamond family, and the cause of their beautiful colour is still somewhat a mystery.
Unlike other fancy diamonds, pink diamonds’ colour is not caused by chemical impurities, and the exact reason for pink stones is uncertain. However, in the gemological world, the pink colour in diamonds is most commonly attributed to the enormous additional pressure these stones undergo during their formation process. The prevailing theory is that the pink is caused by abnormal stress experienced by rough diamonds in the Erath’s mantle, which caused the diamond’s lattice to distort and create graining and pink zones.
Pink diamonds were first discovered in the Kollur mine in India. Later they have been found in Brazil, Russia, South Africa, Tanzania, Canada and Australia. Most often, they have been found in the Argyle mine Kimberley, Western Australia, which has been closed in 2020 because of the increasing operation cost and a stagnant diamond market.
Evaluating the Colour of Pink Diamonds
The colour evaluation of pink diamonds has three main components: hue, saturation and tone.
Hue is the visible colour of a diamond, and the primary hue of pink diamonds is pink. There can also be secondary hues that affect the value of stones. The most common secondary hues present in pink diamonds are purple, brown, orange and yellow, the last two undertones being less desirable.
Secondary hues that enhance the primary hue or do not detract from it add value as a rule, whereas secondary hues that detract from the primary one diminish the price. For example, pink diamonds with purple secondary hue command higher prices than pink diamonds with a brown hue. Natural pink diamonds with no secondary hues are the rarest and the most expensive as a result.
Saturation refers to the intensity of the colour. As a general rule, the more saturated the colour of a diamond, the more valuable it is. That is why diamonds that have vivid pink colour are much more expensive than those with pale or faint colour, as low saturation can appear brown or grey. The most expensive pink diamonds display colour close to red.
This characteristic refers to how light or dark the colour is. The choice of the tone depends on your personal preference; however, the stones that are too dark are not that sought after as they tend to have strong brown secondary hues and are not highly saturated.
A pink diamond’s colour grade is based on both the colour of the stone and its intensity level. According to the GIA, pink diamonds are classified using the following colour grades: Faint, Very Light, Light, Fancy Light, Fancy, Fancy Intense, Fancy Vivid, Fancy Deep and Fancy Dark. The secondary colour is also included in the grade if present.
Evaluating the Clarity of Pink Diamonds
The clarity of pink diamonds is graded the same way as that of colourless stones. The fewer inclusions, the higher the clarity grade.
Of course, high clarity pink diamonds are more valuable, but this characteristic is not crucial for fancy colour diamonds. The pink colour tends to hide imperfections, so the appearance of pink diamonds is less affected by flaws compared to colourless diamonds.
When choosing the clarity of pink diamonds, look for a stone that is eye clean, meaning the diamond should not have inclusions visible to the naked eye. Pink diamonds in the SI1 – SI2 clarity range may look stunning and do not differ significantly from diamonds in VS or even the VVS range.
Evaluating the Cut of Pink Diamonds
The cut quality of pink diamonds, and all fancy colour diamonds in general, is not graded the same way as it is for colourless stones. Unlike colourless diamonds, fancy diamonds are not cut to maximize fire, brilliance and scintillation. These characteristics are considered to be secondary.
Pink diamonds are cut to maximize colour intensity, usually into fancy shapes. In other words, the proportions that are considered ideal for colourless diamonds will not always be the best to bring out the colour of pink diamonds.
Keep in mind that an excellent cut pink diamond costs a premium, so when choosing one, it is better to focus on the stone’s hue, saturation and tone and not judge the diamond using traditional cut grades.
Pink Diamond Rarity and Prices
Natural pink diamonds are one of the rarest colours in the fancy colour diamond family, and they are extremely expensive. Only 0.1% out of the mine’s 20 million carats annual output is classified as pink diamonds. Larger pink diamonds (any stone above 0.2 carats) are even rarer and cost disproportionally more per carat.
For example, four decades ago, fancy light pink diamonds cost $10,000 per carat, while in 2017, the estimated price per carat was $220,000. Vivid pink diamonds were sold for $50,000 per carat 40 years ago, while in 2014, the price was already $600,000 per carat. Nowadays, a high-quality intense pink diamond can cost up to $700,000 per carat.
As you can see, pink diamonds are a good investment because fancy light pink diamonds alone have seen a 15% annual increase in the last decade.