Study yields new insight in hunt for rare, valuable yellow diamonds

A new study by University of Alberta scientists could help guide the search for rare, high-value yellow diamonds in the Canadian North.

The researchers, led by PhD student Mei Yan Lai, examined the chemical makeup of stones recovered from the Chidliak and Ekati mines in Northern Canada to get a better understanding of how they formed.

“Without this research, we wouldn’t know that two separate formation events occurred, and that the second, more recent event is responsible for the yellow colour,” explained U of A diamond geologist Thomas Stachel.

“The more we know about the origin of these potentially high-value diamonds, the better results for diamond exploration and value creation in Northern Canada.”

Lai said they wanted to understand the origin of the yellow colour in the diamonds from the two deposits.

“Canadian yellow diamonds have never been studied spectroscopically in detail. Our results suggest that the cause is the preservation of unstable single nitrogen atoms preserved inside the diamonds,” explained Lai, who conducted this research as part of her master’s studies in the Diamond Exploration Research Training School under the supervision of Stachel.

The research team determined that some yellow diamonds contain colourless cores, meaning that the yellow outer layers crystallized on top of clearer centres. Lai determined that the yellow diamonds crystallized no more than 30,000 years before the kimberlite eruptions that brought them up to Earth’s surface.

“Our analysis shows that the colourless cores in these yellow diamonds are about one billion years older,” Lai said. “In fact, the carbon isotope compositions and nitrogen concentrations of the colourless cores and yellow outer layers are significantly different, suggesting that they formed in at least two distinct events and involved different diamond-forming fluids.”

The researchers said discovering a potential new source of yellow diamonds in the Canadian North is economically significant, as the previous main source of high-quality yellow diamonds, the Ellendale Mine in Western Australia, was recently shut down.

The discovery of colourless cores in some of the yellow diamonds may also be of interest to the jewelry trade, said Lai.

“Occasionally, rough yellow diamonds lose their vibrant yellow colour after being cut and polished—probably because this kind of diamond has a thin layer of yellow overgrowth on top of the geologically older colourless core,” she said.

The project is a collaboration with Dominion Diamond Mines and Peregrine Diamonds Ltd. Part of the analyses were done at the Gemological Institute of America.

The research is supported by a bursary through DERTS, funded by the Natural Sciences and Engineering Research Council of Canada’s Collaborative Research and Training Experience program.

The study, “Yellow Diamonds With Colourless Cores—Evidence for Episodic Diamond Growth Beneath Chidliak and the Ekati Mine, Canada,” was published in Mineralogy and Petrology.

Source: DCLA

Study yields new insight in hunt for rare, valuable yellow diamonds

A new study by University of Alberta scientists could help guide the search for rare, high-value yellow diamonds in the Canadian North.

The researchers, led by PhD student Mei Yan Lai, examined the chemical makeup of stones recovered from the Chidliak and Ekati mines in Northern Canada to get a better understanding of how they formed.

“Without this research, we wouldn’t know that two separate formation events occurred, and that the second, more recent event is responsible for the yellow colour,” explained U of A diamond geologist Thomas Stachel.

“The more we know about the origin of these potentially high-value diamonds, the better results for diamond exploration and value creation in Northern Canada.”

Lai said they wanted to understand the origin of the yellow colour in the diamonds from the two deposits.

“Canadian yellow diamonds have never been studied spectroscopically in detail. Our results suggest that the cause is the preservation of unstable single nitrogen atoms preserved inside the diamonds,” explained Lai, who conducted this research as part of her master’s studies in the Diamond Exploration Research Training School under the supervision of Stachel.

The research team determined that some yellow diamonds contain colourless cores, meaning that the yellow outer layers crystallized on top of clearer centres. Lai determined that the yellow diamonds crystallized no more than 30,000 years before the kimberlite eruptions that brought them up to Earth’s surface.

“Our analysis shows that the colourless cores in these yellow diamonds are about one billion years older,” Lai said. “In fact, the carbon isotope compositions and nitrogen concentrations of the colourless cores and yellow outer layers are significantly different, suggesting that they formed in at least two distinct events and involved different diamond-forming fluids.”

The researchers said discovering a potential new source of yellow diamonds in the Canadian North is economically significant, as the previous main source of high-quality yellow diamonds, the Ellendale Mine in Western Australia, was recently shut down.

The discovery of colourless cores in some of the yellow diamonds may also be of interest to the jewelry trade, said Lai.

“Occasionally, rough yellow diamonds lose their vibrant yellow colour after being cut and polished—probably because this kind of diamond has a thin layer of yellow overgrowth on top of the geologically older colourless core,” she said.

The project is a collaboration with Dominion Diamond Mines and Peregrine Diamonds Ltd. Part of the analyses were done at the Gemological Institute of America.

The research is supported by a bursary through DERTS, funded by the Natural Sciences and Engineering Research Council of Canada’s Collaborative Research and Training Experience program.

The study, “Yellow Diamonds With Colourless Cores—Evidence for Episodic Diamond Growth Beneath Chidliak and the Ekati Mine, Canada,” was published in Mineralogy and Petrology.

Source: DCLA

Super-rich are investing in diamonds

Amid economic uncertainty, the super-rich are looking to ultra-rare precious gemstones as a ‘safe’ store for their wealth

Fine jewellery sales are seeming to weather the coronavirus crisis, thanks to lockdown proposals and demand for precious pieces to mark birthdays and anniversaries. Some jewellers report that people are spending more on gifts than usual, in lieu of ‘proper’ face-to-face celebrations.

And at the high end of the market, collectors are still investing in rare gemstones – sometimes seeing them as a safer store for their money than the volatile stock market or property.

Source: DCLA

Super-rich are investing in diamonds

Amid economic uncertainty, the super-rich are looking to ultra-rare precious gemstones as a ‘safe’ store for their wealth

Fine jewellery sales are seeming to weather the coronavirus crisis, thanks to lockdown proposals and demand for precious pieces to mark birthdays and anniversaries. Some jewellers report that people are spending more on gifts than usual, in lieu of ‘proper’ face-to-face celebrations.

And at the high end of the market, collectors are still investing in rare gemstones – sometimes seeing them as a safer store for their money than the volatile stock market or property.

Source: DCLA

Five GIA Labs Resume Operations

The Gemological Institute of America (GIA) has reopened laboratories in five locations following COVID-19 shutdowns.

The organization’s labs in Johannesburg and Tokyo recommenced limited operations on May 7, the GIA said Monday. Visitors to the Johannesburg lab must make an appointment, have a permit, and wear a mask. The Tokyo location will accept and return goods by delivery only.

On May 11, the GIA resumed operations at its locations in Antwerp and in Gaborone, Botswana. While Antwerp is receiving customers by appointment only, Gaborone is open with a limited capacity to comply with government mandates and allow for proper social distancing, the GIA noted. The lab in Carlsbad, California, reopened May 18, with submission of goods only accepted by shipment.

Labs in Bangkok, Hong Kong and Ramat Gan, Israel, are all open, and are operating with regular hours. Operations in Mumbai, Surat and New York remain closed.

“Our first priority is to protect the health and safety of all staff, clients and visitors,” said Tom Moses, the GIA’s executive vice president and chief research and laboratory officer. “As we work to meet our clients’ needs whenever and wherever possible, we are planning for the safe opening of all other GIA locations as soon as conditions and government authorities permit.”

Source: DCLA

Five GIA Labs Resume Operations

The Gemological Institute of America (GIA) has reopened laboratories in five locations following COVID-19 shutdowns.

The organization’s labs in Johannesburg and Tokyo recommenced limited operations on May 7, the GIA said Monday. Visitors to the Johannesburg lab must make an appointment, have a permit, and wear a mask. The Tokyo location will accept and return goods by delivery only.

On May 11, the GIA resumed operations at its locations in Antwerp and in Gaborone, Botswana. While Antwerp is receiving customers by appointment only, Gaborone is open with a limited capacity to comply with government mandates and allow for proper social distancing, the GIA noted. The lab in Carlsbad, California, reopened May 18, with submission of goods only accepted by shipment.

Labs in Bangkok, Hong Kong and Ramat Gan, Israel, are all open, and are operating with regular hours. Operations in Mumbai, Surat and New York remain closed.

“Our first priority is to protect the health and safety of all staff, clients and visitors,” said Tom Moses, the GIA’s executive vice president and chief research and laboratory officer. “As we work to meet our clients’ needs whenever and wherever possible, we are planning for the safe opening of all other GIA locations as soon as conditions and government authorities permit.”

Source: DCLA

Pink Prices set to Rise with Closure of Argyle

The price of super-rare pink diamonds is to set to rocket with the forthcoming closure of the Argyle mine in Western Australia, which has been responsible for 90 per cent of world supplies.

Owners Rio Tinto plan to cease production by the end of 2020, when economically-viable reserves will run out.
The value of pink diamonds sold at its annual tenders has been appreciating by an average of 10 per annually over the last couple of decades, outperforming all major equity markets. They are a magnet for collectors and investors.
That growth in value is likely to accelerate when Argyle closes, after 37 years in which it became known as the world’s largest supplier of natural colored diamonds – including white, champagne, cognac, blue and violet – as well and the rare and highly-coveted Argyle pinks and reds.
Last year Hong Kong-based Kunming Diamonds bought the Argyle Pink Everlastings Collection comprising smaller Argyle pink and red diamonds totaling 211 carats.

The company’s director Harsh Maheshwari told the South China Morning Post newspaper last week that the price of Argyle Pinks had been insulated even from COVID-19 because of their rarity and the closure of the mine.
Russian miner Alrosa aims to fill some of the gap left in the market but won’t match Argyle’s production.  

Source: DCLA