Diamond Shapes and the Impact of Rough Recovery on Pricing

 

Insights from the Diamond Certification Laboratory of Australia (DCLA)

In the diamond industry, shape is far more than an aesthetic choice. It plays a direct role in value, pricing structure, and how efficiently a rough diamond can be transformed into a polished stone. At the Diamond Certification Laboratory of Australia Diamond Certification Laboratory of Australia (DCLA), one of the key considerations in diamond assessment is how much of the original rough crystal is recovered during polishing.

This recovery rate, often referred to as yield, is one of the hidden drivers behind diamond pricing and helps explain why different shapes are priced differently in the wholesale and retail markets.

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Understanding Rough Diamond Recovery

When a rough diamond is cut and polished, a significant portion of the original crystal is lost. This loss is unavoidable due to the need to remove inclusions, shape the stone, and maximise brilliance.

Different shapes produce different recovery percentages:

• Higher yield shapes retain more of the original rough
• Lower yield shapes sacrifice more material to achieve optical performance and symmetry

This difference directly impacts cost efficiency for cutters and ultimately influences market pricing.

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Round Brilliant Cut: The Lowest Yield but Highest Demand

The round brilliant cut remains the most popular diamond shape globally due to its unmatched brilliance and light performance. However, it also has the lowest average recovery rate, typically ranging from 40 percent to 45 percent of the original rough diamond.

This means that more than half of the rough stone is lost during cutting. As a result, cutters must allocate more rough carat weight to produce a finished round brilliant diamond.

Because of this inefficiency, round diamonds carry a distinct pricing structure. They are often listed on a separate price sheet compared to fancy shapes, reflecting their lower yield and consistently strong market demand.

In practice, this means:

• Higher cost per polished carat
• Separate pricing benchmarks in global diamond trading
• Strong liquidity due to consumer preference

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Fancy Shapes and Higher Recovery Efficiency

Fancy shaped diamonds generally achieve higher recovery rates, often between 50 percent and 70 percent depending on the specific shape and quality of the rough stone.

Common fancy shapes include:

• Oval
• Cushion
• Princess
• Emerald
• Pear
• Marquise
• Radiant
• Asscher

These shapes allow cutters to follow the natural structure of the rough diamond more efficiently, reducing waste and improving yield.

Because more of the rough diamond is preserved, fancy shapes are generally more cost efficient to produce. This efficiency is reflected in their pricing, which is typically lower per carat compared to round brilliant diamonds of equivalent quality.

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Why Shape Drives Price Differences

The difference in pricing between round and fancy shapes is not simply a matter of popularity. It is fundamentally linked to manufacturing economics.

Key factors include:

1. Rough Utilisation

Round diamonds require significantly more rough material per finished carat, increasing production cost.

2. Cutting Strategy

Fancy shapes are often designed to maximise retention of weight from irregular rough crystals, improving overall yield.

3. Market Demand

Round brilliant diamonds remain the most in demand, which further strengthens their premium pricing structure.

4. Inventory and Supply Chain

Because fewer polished carats are produced from the same amount of rough, round diamonds are less efficient to supply, reinforcing their separate pricing benchmarks.

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Separate Pricing Structure for Round Brilliant Diamonds

Due to their unique combination of high demand and low recovery efficiency, round brilliant diamonds are typically priced using a dedicated pricing list in the wholesale market.

This separation reflects:

• Higher manufacturing loss during cutting
• Consistent global demand for round brilliance
• Different valuation dynamics compared to fancy shapes

Fancy shapes, by contrast, are generally grouped within broader pricing frameworks that account for their higher yield and more flexible cutting outcomes.

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Diamond shape is not only a design choice but a critical economic factor in the diamond industry. Recovery rates from rough stone directly influence pricing structures, with round brilliant diamonds standing apart due to their lower yield and strong consumer demand.

At DCLA, understanding these differences is essential for accurate valuation, certification, and market analysis. As the diamond trade continues to evolve, the relationship between rough recovery and polished pricing remains one of the most important principles shaping global diamond values.

Source: DCLA

Rio Tinto closes Argyle diamond mine after 37 years

 

Pink diamonds, already rare, are about to get scarcer as Rio Tinto has closed its iconic Argyle diamond mine, the world’s biggest and the main global source of high-quality pink diamonds.

Since opening its doors 37 years ago, the Western Australia mine produced 865 million carats of rough diamonds and became the source of about 90% of the world’s prized rose-to-magenta hued stones.

The Argyle ore body, a single pipe known as AK1, was discovered in October 1979. Alluvial operations began in 1983, open pit mining kicked off in 1985 and the mine became a fully underground operation in 2013.

Today, Rio has mined the very last of these unique diamonds from the site, located within the ancient Matsu Ranges more than 3,000 km north of Perth.

“Fifty years ago there were very few people who believed there were diamonds in Australia even fewer could have foreseen how the Argyle story would unfold,” Rio Tinto’s chief executive of Copper and Diamonds, Arnaud Soirat, said in a statement.

“To arrive at this final chapter has required vision, courage and determination to overcome significant challenges to enter new territory in diamond exploration, mining and marketing,” Soirat added.

The closure of Argyle will remove about 75% of Rio’s diamond output, yet the impact on the miner’s earnings will be negligible. Diamonds bring in only about 2% of its earnings, while iron ore the company’s main commodity accounts for almost 60%.

The operation will now undergo decommissioning and rehabilitation, which is expected to take five years. After that, Rio will monitor the site for a period yet to be defined.

End of an era

Andrew Wilson, general manager of Argyle, said the mine transformed the diamond sector since its opening, supplying gems for both ends of the market.

“A new chapter will now begin as we start the process of respectfully closing the Argyle mine and rehabilitating the land, to be handed back to its traditional custodians,” he said.

Argyle was Australia’s first large-scale diamond operation, pioneering the fly–in fly–out model, and seen as an opportunity for a workforce drawn from across the nation.

Forty years ago, in the Kimberley region of Western Australia, four diamonds in a dry creek bed ultimately led Rio’s geologists to a massive diamond deposit.

It also triggered the creation and adoption of new technology and exploration methods to make the search for diamonds more efficient across the rugged and remote Kimberley landscape.

At its peak, Argyle churned out 40% of the world’s diamond output, which made it the biggest producer by volume.

Pricy gems

Analysts and auctioneers alike expect prices for pink diamonds to go up and, potentially spur exploration.

Pink stones have already been fetching record prices in the past few years and the closure of their main source could see that trend strengthen.

The “Pink Star” went for $71.2 million at Sotheby’s Hong Kong in April 2017, setting a record for diamonds sold in auctions.

In 2018, the 18.96-carat Pink Legacy fetched $50 million at Christie’s auction house, breaking the world record for price paid per carat for a pink diamond at auction.

The Pink Legacy diamond.

At Sotheby’s Hong Kong 2019 sale, one of the star pieces described as an “exquisite 10.64 carat vivid purplish pink diamond” sold for just under $20 million.

Rio Tinto’s own data show that prices for their Argyle pink diamonds jumped by 500% from 2000 to earlier this year.

Source: DCLA

Rio Tinto closes Argyle diamond mine after 37 years

 

Pink diamonds, already rare, are about to get scarcer as Rio Tinto has closed its iconic Argyle diamond mine, the world’s biggest and the main global source of high-quality pink diamonds.

Since opening its doors 37 years ago, the Western Australia mine produced 865 million carats of rough diamonds and became the source of about 90% of the world’s prized rose-to-magenta hued stones.

The Argyle ore body, a single pipe known as AK1, was discovered in October 1979. Alluvial operations began in 1983, open pit mining kicked off in 1985 and the mine became a fully underground operation in 2013.

Today, Rio has mined the very last of these unique diamonds from the site, located within the ancient Matsu Ranges more than 3,000 km north of Perth.

“Fifty years ago there were very few people who believed there were diamonds in Australia even fewer could have foreseen how the Argyle story would unfold,” Rio Tinto’s chief executive of Copper and Diamonds, Arnaud Soirat, said in a statement.

“To arrive at this final chapter has required vision, courage and determination to overcome significant challenges to enter new territory in diamond exploration, mining and marketing,” Soirat added.

The closure of Argyle will remove about 75% of Rio’s diamond output, yet the impact on the miner’s earnings will be negligible. Diamonds bring in only about 2% of its earnings, while iron ore the company’s main commodity accounts for almost 60%.

The operation will now undergo decommissioning and rehabilitation, which is expected to take five years. After that, Rio will monitor the site for a period yet to be defined.

End of an era

Andrew Wilson, general manager of Argyle, said the mine transformed the diamond sector since its opening, supplying gems for both ends of the market.

“A new chapter will now begin as we start the process of respectfully closing the Argyle mine and rehabilitating the land, to be handed back to its traditional custodians,” he said.

Argyle was Australia’s first large-scale diamond operation, pioneering the fly–in fly–out model, and seen as an opportunity for a workforce drawn from across the nation.

Forty years ago, in the Kimberley region of Western Australia, four diamonds in a dry creek bed ultimately led Rio’s geologists to a massive diamond deposit.

It also triggered the creation and adoption of new technology and exploration methods to make the search for diamonds more efficient across the rugged and remote Kimberley landscape.

At its peak, Argyle churned out 40% of the world’s diamond output, which made it the biggest producer by volume.

Pricy gems

Analysts and auctioneers alike expect prices for pink diamonds to go up and, potentially spur exploration.

Pink stones have already been fetching record prices in the past few years and the closure of their main source could see that trend strengthen.

The “Pink Star” went for $71.2 million at Sotheby’s Hong Kong in April 2017, setting a record for diamonds sold in auctions.

In 2018, the 18.96-carat Pink Legacy fetched $50 million at Christie’s auction house, breaking the world record for price paid per carat for a pink diamond at auction.

The Pink Legacy diamond.

At Sotheby’s Hong Kong 2019 sale, one of the star pieces described as an “exquisite 10.64 carat vivid purplish pink diamond” sold for just under $20 million.

Rio Tinto’s own data show that prices for their Argyle pink diamonds jumped by 500% from 2000 to earlier this year.

Source: DCLA

Gem Diamonds sixth large rough diamond for this year

Gem Diamonds at an elevation of 3,100 meters above sea level, The Letšeng Diamond mine is one of the world’s highest diamond mines.

The Letšeng Diamond Mine is having an extraordinary year this far as the miner continues to recover rough diamonds larger than 100 carats at its mine in Lesotho.

On Wednesday, the company announced it had recovered a 152 carat  D colour type IIa diamond, the sixth exceptional large rough diamond so far this year.

Source: DCLA 

Gem Diamonds sixth large rough diamond for this year

Gem Diamonds at an elevation of 3,100 meters above sea level, The Letšeng Diamond mine is one of the world’s highest diamond mines.

The Letšeng Diamond Mine is having an extraordinary year this far as the miner continues to recover rough diamonds larger than 100 carats at its mine in Lesotho.

On Wednesday, the company announced it had recovered a 152 carat  D colour type IIa diamond, the sixth exceptional large rough diamond so far this year.

Source: DCLA