Are Diamonds Really Forever?

Q. Will a diamond look the same in a billion years? What happens to these giant carbon molecules over very long periods of time?

A. It depends on where the diamond spends those years, said George E. Harlow, a gem curator at the American Museum of Natural History, who is also an adjunct senior research scientist at the Lamont-Doherty Earth Observatory of Columbia University.

Rough diamond crystalsDiamonds, which form eight-sided crystals called octahedrons, can be billions of years old, Dr. Harlow said. They are datable by minute inclusions of other minerals, retained inside them since they were formed deep in the Earth.

“Lots of ancient diamonds that have been down there for close to two billion years will still look like octahedrons,” Dr. Harlow said.

“But the Earth is dynamic, moving all the time and most diamonds show the effects of being squooshed to some extent,” he said. “They are not inert, but may deform and crystallize again.”

As the crystals are squeezed and heated, the molecular bonds are weakened, with the edges and flat surfaces of the crystals being particularly vulnerable, Dr. Harlow explained. Many diamonds end up with rounded shapes rather than being sharply defined.

As the internal planes of the crystal slide past one another, tiny cavities may be created because atoms are missing from the crystal structure. It is these cavities that are believed to create a brown or pink color, Dr. Harlow said. As for very rare red diamonds, the theory is that they are the result of cavities of a very uniform size.

“If a diamond gets raised to a shallower level or heated a lot,” he said, “it may wind up being in the stability field of graphite, the more common form of carbon. We know this because there are plenty of documented cases of graphite with the shape of a diamond.”

Diamonds that reach the surface are often blasted there very quickly, at speeds of 30 to 50 miles per hour by volcanic elevators called kimberlites, Dr. Harlow said. If these elevators are too slow, however, that leaves diamonds vulnerable to being dissolved in the fluid they are brought up in. The sharp edges go first.

“Once they are near Earth’s surface, it is very difficult to get rid of diamonds,” Dr. Harlow said. They are very stable at low temperatures, and the amount of energy required to break their bonds and change them is not available, so they would essentially stick around in the same form forever. question@nytimes.com


$13 Diamond Ring Sells for $850,000

26.29 ct costume-diamond-1London--The owner of a diamond ring long believed to be an essentially worthless piece of costume jewelry saw the ring sell for more than $800,000 on Wednesday at Sotheby’s London.

The buyer, who wishes to remain anonymous, paid 10 British pounds (about $13) for the ring in the 1980s, buying it at a car-boot sale, a sale where people look to offload unwanted items out of the trunks of their cars.  

She wore it for decades to do chores and run errands, unaware that what she was wearing wasn’t a piece of cheap glass but a big, high-quality diamond. The stone’s old-fashioned cut and dark setting (it was set in a silver mounting that had tarnished) were likely why the ring’s owner didn’t know what she had, Sotheby’s said prior to the sale.

Then, one day, a local jeweler spotted the ring on the woman’s finger and, thinking it could be a real diamond, suggested she get it appraised.

She did and it turned out the jeweler was right--it was a real diamond, a 26.29-carat cushion-shaped stone graded as I color and VVS2 clarity by the Gemological Institute of America.

26.29 ct costume-diamond-2The diamond dates to the 19th century, though nothing is known of its history prior to its purchase in the 1980s.

At Sotheby’s Fine Jewels sale held Wednesday in London, a buyer paid 656,750 British pounds (including buyer’s premium), or about $851,000, for the ring.  

It was the top item in the sale, topping its highest pre-sale estimate by $400,000.

The buyer of the ring, which Sotheby’s referred to as the “Tenner” diamond because of the original price paid (10 British pounds), was identified by the auction house only as a member of the international trade. 

Sotheby’s Fine Jewels sale totaled 5.2 million British pounds ($6.7 million) and was 80 percent sold by lot.

The second highest-grossing lot of the sale was a Cartier diamond brooch that former British Prime Minister Margaret Thatcher wore on a number of high-profile public occasions, including the day she offered her resignation to the queen.

The brooch sold for 81,250 British pounds ($105,308), more than three times its highest pre-sale estimate. Proceeds from its sale will go to the Endeavour fund, a charity that supports the recovery of wounded, injured and sick servicemen and women.

via www.nationaljeweler.com


Man finds 2.78-carat diamond at Arkansas state park - ABC News

2.78 ct Crater of Diamonds State Park-1One man found the perfect last-minute Mother's Day gift for his wife when he spotted a small rock that turned out to be a diamond.

"When I told her I was going to find her a diamond for Mother's Day I didn't know I would actually find one," Wendell Fox told ABC News about his find at the Crater of Diamonds State Park in Murfreesboro, Arkansas, on May 13. "I sort of pre-committed so I had to follow through," he said.

Fox, 70, and his wife Jennifer, 68, live in Joliet, Montana, most of the year, but as Arkansas natives, the pair knew the storied history behind the state park. "The diamond mine is part of Arkansas history and it's the only one in the U.S." he explained, unaware that the park had been a hotbed for other diamond-seekers in recent months.

Fox said he and his wife were walking around the grounds for about an hour and a half "looking for a glimmer" when he noticed the gem.

"I was surface looking, walking very slowly and looking very slowly and I saw it," Fox said. "I got down for a closer inspection because I wasn't quite sure what to look for, but as soon as I saw it I thought, 'that's probably a diamond.'"

2.78 ct Crater of Diamonds State Park-2Fox showed the peanut-sized stone to his wife who told him to take it to the Diamond Discovery Center. When Fox pulled it from his pocket to show the employees, "one of the ladies sort of gasped and I just saw this big smile," he said.

The staff confirmed that Fox discovered a 2.78-carat champagne colored diamond, the second-largest one registered at the park this year.

Fox named his gem "Way Out Yonder" as a tribute to their home in Montana. The gemstone will be made into a pendant for his wife, Jennifer.

"We still can't believe that we found it. It was just by the grace of God and love," Fox said.

via abcnews.go.com


Christie’s Sells 92ct. Heart Pendant for $15M

Christies heart diamondThe largest heart-shaped, D-flawless diamond ever offered at auction fetched $15 million at Christie’s in Geneva on Wednesday, the company reported.

The 92.15-carat diamond, which was mounted in a necklace, achieved $162,611 per carat, falling within its pre-sale estimate of $14.1 million to $20.2 million. The piece, dubbed “La Légende,” was a creation of Boehmer et Bassenge, a high-end maison launched last year and named after 18th-century Parisian jewelers Charles Boehmer and Paul Bassenge.

Other sales at the auction included a ring set with diamonds and an oval-cut, 15.03-carat ruby, which garnered $12.9 million. Separately, a cushion-shaped, 7.97-carat, fancy intense blue, VS1-clarity diamond went for $12.7 million, or $1.6 million per carat.

The Magnificent Jewels auction recorded total proceeds of $95 million (CHF 93.1 million) including buyer’s premiums. It came a day after rival Sotheby’s sold $151.5 million of jewelry at its Geneva event, headlined by a pair of earrings that fetched a record $57.4 million, or $2.9 million per carat.

via www.diamonds.net


Chunk That Broke Off 1,109-Carat Diamond Sells for $17M

 Vancouver, British Columbia--A 373.72-carat rough diamond that once was part of the second largest piece of rough ever found sold for $17.5 million last week, Lucara Diamond Corp. reported.

373.72 rough diamondThe diamond was one of 15 single-stone lots offered at the diamond mining company’s first “exceptional” stone tender of the year.

Graff Diamonds purchased the stone, posting a photo of the rough on its Instagram account over the weekend.

Lucara found the 374-carat diamond in November 2015at its Karowe mine in Botswana at the same time it discovered the record-setting, 1,111-carat diamond (now 1,109 carats) that would come to be known as Lesedi la Rona. 

CEO William Lamb said that had the smaller, 374-carat piece of rough not broken off the main stone, the diamond would have weighed almost 1,500 carats. But the huge rough diamond likely would have been crushed in the company’s recovery plant, which isn’t designed to handle stones of that size.

“If the 374-carat stone was still attached to the Lesedi, the stone would have been larger in two dimensions than the largest screen (sieve) used in the plant to separate material into different sizes,” he explained. “The original stone would have been too large to pass through the screen and the whole stone would have ended up in the crusher, where it would have been broken into a lot more pieces.”

He added that Lucara is currently in the process of upgrading its plant, an upgrade called mega diamond recovery or MDR, which will address this by recovering diamonds up to 5,000 carats right at the front of the process facility.

Also recovered from that fortuitous haul was an 812.77-carat diamond that sold for $63.1 million--more than $77,000 per carat--in May 2016, setting a new world record for a rough diamond.
 
The 374-carat diamond was the top lot in the Lucara’s tender, which was 100 percent sold by lot.

The sale, which contained rough diamond ranging from 374 to 29.9 carats in size, totaled $54.8 million, or $31,010 per carat.

Lucara said there were seven diamonds that sold for more than $2 million each. Of those, three diamonds topped $4 million.

182 carat rough diamondThis includes the 374-carat diamond and the auction’s second highest-grossing lot, a 182.47-carat diamond that sold for $6.3 million.

Since it started mining at Karowe in 2012, Lucara has gotten more than $1 million for each of 145 rough diamonds.

Its biggest find remains unsold, however.

Lesedi-la-Rona rough diamondThe 1,109-carat Lesedi la Rona went up for public auction at Sotheby’s but nobody met the $70 million reserve price.

At the end of 2016, Lamb told National Jeweler that the rough diamond likely would be put up for sale again in 2017 but through a sealed bid tender, perhaps, and not a public auction.

When asked about the diamond on Monday, Lamb said: “We continue to speak to a number of people within the sector regarding the sale of the stone, as well as looking at options to partner to polish the stone or even polish it without a partner … We are looking at all options and hope to make a decision soon.”
 
 
By Michelle Graff

Coloured stones: Collecting guide | Christie's

From rubies and emeralds to rare coloured diamonds

Specialist David Warren provides an in-depth expert guide for buyers seeking a bright addition to their collection



1) Fancy or Vivid? Get to know your terminology
Colored GemstonesA highlight in the coloured stones category — often setting world-record prices — coloured diamonds come with their own specific colour categories. A blue diamond, for example, could be classified as Faint Blue, Very Light Blue, Fancy Light Blue, Fancy Blue, Fancy Intense Blue, Fancy Dark Blue, Fancy Deep Blue or Fancy Vivid Blue. The same principle of categorisation applies to coloured diamonds of virtually all hues.


2) Word order is important
Coloured diamonds aren’t always a single colour. You may sometimes see a diamond described as ‘Vivid Orange Yellow’ — or even ‘Vivid Yellow Orange’. But what’s the difference? The key here is to look at the last word, which will be the principal colour. A pair of Vivid Orange Yellow diamond earrings were recently sold by Christie’s in Geneva, for example, where the colour was considered marginally more towards yellow than orange.

You can also have an ‘Orangey Yellow’. Here, yellow remains the dominant colour, with just a touch of orange; it’s not as orange as an ‘Orange Yellow’.


3) Are some colours more valuable than others?
The rarest of the rare is a red diamond — there aren’t many, and they’re generally not very big. It would be exceptionally unusual to find a red diamond above 2 carats.


4) How are coloured diamonds graded?
Christie’s sends diamonds to the GIA laboratory (the Gemological Institute of America), which provides the world’s most trusted colour grading service. It’s often worth doing, even if you have a stone with a weak colour — particularly if the colour is faint pink, green or blue, for example, which could still be significantly valuable.

A weak yellow diamond, however, might not be, as it is not uncommon to find stones with a yellow tinge. Other colours that may still be attractive and collectable but far less expensive include brown, yellowish brown, greenish yellowish brown, brownish yellow, yellowish brownish green. There are many colour combinations — even black.


5) Where do coloured diamonds come from?
Mining coloured diamonds is really a matter of chance. The only exception is the Argyle mine in Australia, owned by Rio Tinto, which is the only mine in the world to consistently produce pink diamonds, and is also the world’s largest supplier of natural coloured diamonds.

Diamonds in their purest form are white — as are all other gemstones, except three: opal, turquoise and peridot. What turns them a particular colour is the presence of an accidental colouring agent. A blue diamond, for example, will contain a tiny amount of boron in the composition of the stone. Green diamonds acquire their colour from radiation in the ground, while yellow diamonds are created when nitrogen enter their chemical composition. Pink diamonds result from a ‘slip’ in the stone’s lattice structure.
6 What about other coloured stones? Is there such a thing as a perfect emerald?
When it comes to emeralds, the most coveted are a darkish green. It’s important the stone isn’t too dark, however: the highest-quality emeralds combine good colour with clarity. Imagine if you were to take an empty wine bottle made from green glass and hold it up to sunlight — that’s a good indication of the perfect shade.

The proportions of an emerald (or any gemstone) are also important. If they’re poor, light will diffract and go through the stone, rather than bouncing around within it, coming out, and hitting the eye — a phenomenon known as total internal refraction. While fissures, known as ‘inclusions’, are common, too many will affect the beauty of the stone and lower its value.

Although highly rare, it is theoretically possible to get an emerald so perfect in terms of colour, clarity and brightness that it comes close to resembling the brilliance and ‘fire’ of a diamond (I have only ever seen a handful of emeralds that fall into this rare category).


7) What about rubies and sapphires?
The same concerns apply — as with emeralds, buyers of rubies and sapphires should look for stones with an appealing colour, good clarity, and attractive proportions.

A small percentage of the top rubies have a colour referred to as ‘pigeon’s blood’ — a dark red — though must not be too dark. Aim for a rich, warm burgundy that makes you joyful when you look at it.


8) Is origin relevant?
For coloured gemstones, this is a point to be considered, with the top emeralds mined in Colombia, the finest rubies coming from Burma and, for sapphires, the cream of the crop hail from Kashmir. However, it is important to remember that attractive gemstones do come from many different localities, and it is all about the beauty of the colour and the budget available.


9) How important is carat?
It’s a common misconception to think that stones with a higher carat weight are always more valuable. They often are, but you could have a 50-carat emerald that’s worth say $500 per carat — or a five-carat emerald worth $30,000 per carat. The same is true for all stones. It’s a combination of the ‘four c’s’: colour, clarity, cut and carat weight.


10) Should I be wary of treated stones?
Man has a long history of tampering with coloured stones. Emeralds, for example, often have fissures that break the surface, which can be filled with oil or plastic resin. The oil or resin is designed to have the same refractive index as the stone and, once absorbed into the fissures, the inclusions become less apparent. This practice is one that goes back 4,000 years to Ancient Egypt, when natural oils were used.

The degree to which an emerald has been improved with an enhancement agent is graded from none to insignificant, minor, moderate or significant. Oil, though considered to be gentler, can have the disadvantage of leaking from the stone over time, unlike resin, which is permanent. There’s nothing wrong with buying an enhanced stone, as long as the degree of enhancement is reflected in the price — though a beautiful untreated emerald will be worth far more than a beautiful treated emerald.


11 What about coloured diamonds?
Buyers should ensure that the diamond’s colour is natural. Concerning green diamonds, it’s important to verify that the radiation that gave the stone its colour occurred in the ground, and not in a laboratory — one of the hardest tests for the GIA to determine.

Blue diamonds can also be created through artificial irradiation, but mostly look obviously wrong. Similarly, the colour of yellow stones can be enhanced, with the most famous example of an enhanced stone being the Deepdene Diamond, weighing 104.52 carats.


12 How should I care for coloured stones?
One golden rule is: never carry gemstones in a pouch. Sadly, it’s something I’ve seen too often, and results in badly damaged stones. The resistance of minerals is assessed using ‘Mohs scale of hardness’. If stored with other stones, a diamond will scratch another diamond, and any stone softer than it. Sapphires will scratch everything that is softer than them, and so on, down the scale.

It’s a mistake, however, to think that diamonds are indestructible. Although they are the hardest substance known to man, they do have a certain brittleness. A diamond can chip, for example, if it hits a hard surface like marble. Here, weight becomes critical: if a diamond is damaged, it can be re-cut to remove any chips, but in doing this there will be a loss of weight. If a stone weighing 10.05 carats drops to 9.95 carats, the impact on value can be significant, because it has dipped below 10.00 carats. A loss of half a carat in a 15.75 carat stone, on the other hand, may do little to alter value.

via www.christies.com


Countries That Produce the Most Diamonds

Despite a market that accounts for more than a third of global demand for the gemstone, the U.S. does not have any significant natural diamond resources within its geographical borders. Instead, Russia supplied about a third of the total carats mined in 2015.

Diamond production levels have remained steady in recent years, but industry analysts have predicted a dip in demand due in part to shifting preferences among millennials. The generation is getting married later, if at all, and has unique preferences.

In October, the Diamond Producers Association – a group of seven major diamond retailers, including De Beers and Canada's Lucara – launched an advertising campaign targeting millennial consumers called "Real Is Rare." The industry organization, founded in 2015, even got celebrity Nick Cannon involved.

Diamond-mines-map

But diamonds may not be as rare as the trade organization makes them out to be. After a drop in production between 2008 and 2009, more than 120 million carats of diamond have been produced each year by a handful of countries, largely concentrated in sub-Saharan Africa. According to the U.S. Department of the Interior, there are also "substantial" reserves of the gemstone around the world.

 

Here are the countries that produced the most diamonds in 2015, according to the Kimberley Process Certification Scheme, a collaboration among government and industry organizations.

Country Diamond Production in 2015 (in carats) Average Value Per Carat
Russia 41.9 million $101
Botswana 20.8 million $144
Dem. Rep. of Congo 16.0 million $8
Australia 13.6 million $23
Canada 11.7 million $144
Angola 9.0 million $131
South Africa 7.2 million $193
Zimbabwe 3.5 million $50
Namibia 2.1 million $591
Sierra Leone 500,000 $309
 

The Hidden Meaning Behind Your Favorite Gemstones - Vogue

Gemstones-and-their-meaningsWhile fine jewelry is usually high in monetary value, what often makes it exceptional is that it’s steeped in significance. A piece of jewelry frequently has a particular aura that does not fade; it is with it that we mark the milestones of our lives—engagement, marriage, friendships, parenthood, birthdays, travels, traditions, and love.

Jewelry, some argue, emblematizes the sublime.

When we consider some of the materials jewelry is made with—metals derived from the earth’s crust and gemstones, which, like crystals, have significant metaphysical properties—it’s hard to deny the cosmic allure.

These materials have been honored, according to Maria Leach’s Standard Dictionary of Folklore, Mythology, and Legend, “back beyond recorded history.” Ancient Roman texts note that Cupid’s arrows were tipped with magical diamonds. In Eastern narratives, dragons were often depicted with flaming, wish-granting pearls under their chins or in their claws. In early written accounts, people adorned themselves with feathers, bones, shells, and colored pebbles. We now, of course, refer to these arrangements of naturally occurring materials as jewelry—and now, the colored pebbles are known as gemstones.

Here, a look at the history of some favorite gemstones and their mythological meanings.

Ruby
In Sanskrit, the word for ruby is ratnaraj, or “king of precious stones.” In ancient Hinduism, it was believed by some that those who offered fine rubies to the god Krishna could be reborn as emperors. Rubies were divided into four castes. The Brahmin, for example, granted the advantage of perfect safety. The stone is also mentioned at least four times in the Bible, usually as a representative of beauty and wisdom. Numerous early cultures believed, because of the stone’s likeness to the color of blood, that rubies held the power of life. Among European royalty and the upper classes, rubies were thought to guarantee good health, wealth, wisdom, and success in love. They’ve became some of the most sought-after gems.

 

Lapis
Lapis lazuli has always been associated with royalty and deities, and it may be where the idea of royal blue came from. Egyptians believed that it came from the heavens and provided protection in the afterlife, so they used it in their statues of the gods, in totemic objects, in jewelry, and in burial masks. In the epic poem Gilgamesh, Sumerians spent years traveling from one end of Asia to the other in order to mine and obtain the stone. Lapis is included in numerous other myths but has served practical purposes as well: Ancient Egyptians used it to create blue cosmetics, and during the Renaissance, painters ground the

via www.vogue.com


Pink Star diamond sets new world record in Hong Kong - BBC News

Pink Star diamondA rare diamond known as the Pink Star has been sold in Hong Kong for more than $71m (£57m), setting a new world record for any gemstone at auction.

The oval-shaped 59.6 carat stone was bought after just five minutes' bidding at Sotheby's, reports said.

It is the largest polished diamond in its class to go under the hammer.

It sold for $83m in Geneva in 2013 but the buyer later defaulted. The record until now was held by the Oppenheimer Blue, which sold for $50m last May.

Bidding for the gem, which was found by De Beers at a mine in Africa in 1999 and cut over a period of two years, began at $56m.

Sotheby's said the buyer was Hong Kong jewellery retailer Chow Tai Fook Jewellery.

Alexander Breckner, head of diamonds at jewellers "77 Diamonds", told the BBC that the stone was exceptional.

"It's the largest pink diamond ever found in the history of humankind. It's an incredible colour to it.

"And the sheer size of the stone already makes it so rare and so beautiful."

via www.bbc.com