Tracing the History of Pink Diamonds

Humans have valued diamonds for thousands of years. These beautiful gemstones are rare, difficult to produce and require dedicated craftsmanship. This makes them highly prized as a symbol of wealth and love.

In modern times, the diamond market is worth billions of dollars, with the largest and most vibrant stones being worth the most.

Within this market, pink diamonds are some of the rarest and most popular, making them a prized choice for investors and jewellers.

In this article Australian pink diamond expert, The Diamond Jewellery Studio, will explain how they’re graded and valued prior to sale.

Where Do Pink Diamonds Come From?

Coloured diamonds are some of the most valuable gemstones on Earth. Among coloured stones, pink diamonds are incredibly rare, and the mystery of their formation makes them all the more valuable.

Most of the world’s pink diamonds were sourced from the now-defunct Argyle Diamond Mine. In fact, the Argyle Mine was responsible for producing an estimated 90% of the world’s supply.

While the mine has since closed, pink diamonds are still being mined at sites around the world. Some of the largest suppliers of pink diamonds are located in:

• India
• Brazil
• South Africa
• Russia
• Canada

These mines produce relatively few pink diamonds, and they are typically smaller and less richly coloured than stones that were taken from the Argyle Mine. For this reason, Australian pink diamonds still command the highest market value, and they’re expected to be popular for decades to come.

The History of the Argyle Diamond Mine

The Argyle Diamond Mine was located in Western Australia. Operated by Rio Tinto, the site was the world’s largest diamond mine for almost 40 years.

During its lifetime, the Argyle Mine produced over 750,000 carats of rough diamonds. These were used for both jewellery and industrial purposes.

While the Argyle Mine was highly productive throughout its lifetime, it was best known for providing a steady supply of pink diamonds. At the time of their discovery, pink diamonds were incredibly rare, and Argyle is credited with creating a demand for the coloured stones.

Argyle promoted its pink diamonds by releasing an annual collection that was only available by invitation. At the event, buyers, investors and gemological figures were invited to inspect the finest pink diamonds from that years’ production, with many of the gems being available for purchase.

This tradition continued into the 2000s. While the mine began to produce fewer diamonds during this time, the Argyle company began to slowly release its stockpiles.

The Argyle Diamond mine ceased operations in November of 2020, just 3 years shy of its 40th birthday. The last of the mine’s diamond stocks were officially released in 2022.

This has had a major impact on the value, reputation and rarity of pink diamonds.

The Argyle Grading System

Pink Diamonds are graded according to the 4Cs of diamonds – Cut, Colour, Clarity and Carat weight. These directly affect the quality and value of the diamond.

But the unique colouration of pink diamonds isn’t accurately captured by this traditional scale. To reflect this, the Argyle company developed its own grading scale which assessed the quality and colour of its diamonds.

On the Argyle scale, pink diamonds were categorised into one of three hues:

• Purplish Pink – Pink diamonds with a purple tint
• Pink – Pink diamonds with a pure pink tint
• Pink Rose – Pink diamonds with a red tint

Of these, pure pink diamonds are the most valuable, while diamonds with a red tint are less common.

Within each colour category, diamonds can be further sorted on a 1-9 scale representing the intensity of the huge. The 1-9 scale was developed by the Gemological Institute of America. The grading scale is as follows:

1. Very intense
2. Intense
3. Strong
4. Medium
5. Medium light
6. Light
7. Very light
8. Blush
9. Light blush

The greater the colour intensity, the higher the value of the gemstone.

How Pink Diamonds are Formed

There is no scientific consensus on how pink diamonds are formed.

In most cases, coloured diamonds are created when trace elements become trapped in the crystalline structure of the stone. For example, blue diamonds contain trace amounts of boron.

Pink diamonds are unique in that they are pure carbon, like white diamonds. Their colour doesn’t come from any external element.

Current theories suggest that the pink hue is produced by a misalignment in the diamond’s crystal lattice. This affects how light is refracted, creating a pink tone. This likely means that the shade of pink is related to the scale of the crystal misalignment – e.g. diamonds with greater misalignment are more colourful.

The Value of Pink Diamonds in the Future

Pink diamonds are among the world’s most valuable coloured stones, second only to red diamonds. Their value is due to their rarity and the closing of the Argyle Diamond Mine, which substantially reduced the world’s supply.

The popularity of pink diamonds in jewellery also affects their value. These gemstones are a prized selection for engagement rings, which is increasing demand and reducing supply.

These factors mean that pink diamonds are very likely to continue increasing in value over the coming decades. Because the mechanism for creating pink diamonds is unknown, gemologists can’t precisely locate new sources, which makes it difficult to start new mining ventures.