The Allure of Asscher Cut Diamonds

There are a number of very enchanting antique and vintage cut diamonds that we all know and love – old miners, old Europeans, rose cuts and cushion cuts to name a few. But the most coveted and hardest to find is the Asscher cut diamond – mostly because a limited number were cut in the early 20th century before production ceased. The story of the famed Asscher cut can be traced back to the Asscher family in Amsterdam in the mid 1800s.

The company was founded by Joseph Isaac Asscher in 1854 as IJ Asscher Diamond Company. As the years progressed, Joseph Isaac’s sons – Joseph and Abraham – came into the business and changed the name of the firm to the Asscher Diamond Company. The firm became one of the most prominent diamond cutting businesses in the world. By the turn of the century and early 1900s, Amsterdam was the preeminent global diamond cutting center teeming with cutters and business. And the Asscher family was at the center of it all.

Famous Diamonds

In 1903, Abraham Asscher was tapped to cut the Excelsior Diamond, which at 995-carats was the world’s largest diamond at the time. Discovered in 1893, the diamond languished in a vault for ten years due to some legal issues. When it finally came out of the vault, the diamond was cut into 11 stones, three of which were purchased by Tiffany & Co.

A couple of years later in 1905, the Excelsior’s place as the largest diamond was usurped by the Cullinan which weighed in at an astounding 3,106-carats. The Cullinan diamond was given to King Edward VII, in 1907 as a birthday gift from South Africa’s Transvaal Colony government. King Edward sought the advice of Joseph Asscher on how to best cut the diamond. After much studying and the development of some new tools to cut the diamond, Joseph Asscher cut the rock in 1908. Nine of the polished gems were presented to King Edward and remain in the British Crown Jewels today – The Great Star of Africa and the Smaller Star of Africa were the two largest. The remaining 96 smaller stones stayed with the Asscher Diamond Company as payment for services.

The Asscher Cut Debuts

In 1902, Joseph Isaac’s grandson, also named Joseph, cut the first diamonds that would bear the family name. The Asscher cut was very different from other cuts of the era which tended to be more round and curvy. The Asscher broke with tradition and was a square, with cut corners that created an octagonal shape giving it a distinctly different look and feel from other diamond cuts that were already available. The cut was so unique that Joseph Asscher had it patented, making it the world’s first patented diamond cut.

Its square shape is not the only trait that sets the Asscher cut apart from other diamonds. It was also the extraordinary sparkle of the stone that comes from the cut corners that allow more light return in the diamond. The Asscher cut is similar to an emerald cut in that they are both step cuts, however an emerald cut is rectangular. The Asscher is distinguished by 58 facets, with a high, two-step crown and a deep pavilion. When you look straight down into the diamond from the top, you will see an “X” that is formed by equidistant converging facets, earning the cut the nickname “hall of mirrors” for the amazing light reflection in the stone.

Art Deco era jewelers were enthralled by the Asscher cut and it became one of the most important diamond cuts of the day. Its square shape was new and modern at the time and its linear architectural form was the perfect complement to the straight geometric lines of the jewelry that was being made in the 1920s and 1930s. The Asscher Diamond Company was thriving.

The End and a New Beginning

When World War II ravaged Europe, the Nazis invaded Holland, stormed Amsterdam and arrested the Asscher family and most of the few hundred employees at the company, all of whom were sent to concentration camps. At the end of the war, ten surviving members of the Asscher family returned to Amsterdam as did about 15 of their cutters. The city’s diamond industry had been gutted.

The Asscher family resolved to rebuild their business. And they did, but they stopped cutting the original Asscher. In 1980 the firm was given the Dutch Royal Predicate from Queen Juliana of the Netherlands. The company changed its name to the Royal Asscher Diamond company. A number of years later the firm introduced the Royal Asscher cut, designed by Joseph Asscher’s great grandnephews, Edward and Joop, which was based on the original cut. Sixteen more facets were added to the design for a total of 74 facets that give the diamond extra shimmer.

The firm continues to cut diamonds today with the fifth and sixth generations of the family at the helm, operating at Tolstraat 127, Amsterdam, the same building where the company started in 1854.

Featured image (top of page): Asscher Cut diamond, 1.87-carats, F/VS2, set in platinum with diamonds and natural Burmese rubies, signed Yard, circa 1935, courtesy Berganza Limited.

Authored by Amber Michelle

The Magic is in the Cut

When it comes to the 4C’s – carat weight, color, clarity and cut — cut is perhaps the most important one. Whether you are aware of it or not, you’re noticing cut, it’s what makes a stone sparkle spectacularly or fall flat. You may look at a diamond and think it looks amazing, or you may look at it and think that something is not quite right —  again it is often cut that you are perceiving. Legendary diamantaire William Goldberg was a strong proponent of cut bringing out the beauty in a diamond and he coined the eponymous firm’s tagline “The Magic is in the Make”. Make is a diamond dealer’s shorthand for cut.

What is Cut?

So what exactly does cut mean? Cut is the arrangement of facets on a stone, while shape is the geometric form – round, pear, marquise, etc. — that is created during the cutting process. Cut is what gives a stone sparkle and brilliance – the return of white light that makes a diamond bright and lively. A skilled diamond cutter can take a rough diamond that is not so great and make it into an amazing gem. So what exactly is a good cut and how does a cutter know what to do?

Master diamond cutter William Lopez, of William Goldberg  talks about what he looks for when he starts to cut a diamond. “When I look at any rough diamond, I decide what will be the biggest, cleanest stone that I can get from the rough,” explains Lopez, who has been cutting diamonds for 52 years. “Then I look at the options, will it be round, emerald or cushion and I give my opinion as to the best way to cut the rough.”

Cut Gives Diamonds Character

According to Saul Goldberg, president of William Goldberg and the second generation in the family business, cut is subjective, each person will have a different opinion about what they like. Cut, he says, is what gives a diamond its character. “A diamond can look great on paper, such as a 10-carat D, flawless, but if it doesn’t have the right cut, it won’t look right when you see it.”

Referencing fancy shape diamonds (anything that is not round) William Goldberg, executive vice president Barry Berg, notes that “the brilliance and life of a diamond is determined by the cut, each cut has to be shaped a certain way to look its best.” That means that not only do the facets on the diamond need to be placed optimally, but the end result has to have the right proportions. Those proportions will vary depending upon the shape of the stone, but generally you want a gem that is not stubby or too elongated.  

“With cut you are trying to get the best brilliance and refraction of light,” agrees Lopez, whose father was a diamond cutter who learned the trade in Puerto Rico and then came to New York City to work. “A cutter is dealing with angles. Top to bottom and bottom to top, certain angles reflect light better. If a stone is too deep on the bottom it will be dark, if it is too shallow it will look glassy. There has to be light bouncing back from the facets to create sparkle.”

Benjamin Goldberg, chief gemologist at William Goldberg is Saul’s son and the third generation to be part of the business, has a slightly different take on the topic. “Cut is a visual aspect of a stone,” he notes. “But clarity can be more important. No one wants to see imperfections.”

Still a well-cut diamond can in some instances minimize the imperfections in a diamond, depending upon where they are in a piece of rough, they can be eliminated altogether or they may land in an area of the finished diamond that is less intrusive.

What Makes a Well Cut Diamond?

So back to our first question, what makes a well cut diamond? “For me, the angles, polish and symmetry all have to be really good. I put a little bit of me into each stone,” says Lopez who learned to cut diamonds from a cutter and friend — Tony Borrero —  who worked in the shop where his dad worked. “Every cutter does something a bit different. It comes from my experience and what I’ve learned over the years. It’s almost a signature. With round stones you pretty much go by the angles, but with fancy shapes you can put more of your artistry into it.”

Ultimately the beauty of cut is, like so many other creative expressions, a highly personal decision based on your own tastes and what your eye perceives as beautiful. At William Goldberg the company principals agree that they prefer to sell a diamond in person, where someone actually looks at the stone rather than selling it based on a gemological laboratory report.

“It comes down to the beauty and character of a diamond,” concludes Saul Goldberg. “You can’t be hung up on the grading report. You have to look at the stone and see how it strikes you. Is it sexy? Does it look good? The stone will talk to you. After all the magic is in the make.”

Featured video (top of page): Diamond cutter William Lopez, from William Goldberg, cutting a diamond.

Authored by Amber Michelle

Colored Diamonds: Rarity and Value

Colored diamonds, also known as fancy colors, are among the rarest and most valuable of all gemstones and they come in an endless kaleidoscope of divine colors. According to the Gemological Institute of America (GIA), only one in every 10,000 diamonds found has a fancy color. And of those even fewer are the vibrant colors that are most desired and of course the most pricey.

Up until the middle to late 1990s colored diamonds were shunted to the side and pretty much ignored. As the 1990s progressed colored diamonds began to appear at auction and their marketing machines put these superpowered gemstones into the spotlight. People began to take notice and colored diamonds started to gain in popularity as consumers began to understand more about their beauty, value and rarity. Today, colored diamonds at auction command prices that soar to breath-taking heights. To give you an idea of just how high prices can go, the Pink Star, a 59.60-carat  vivid pink diamond sold at Sotheby’s Geneva for $71 million in 2017. The year before that, the Oppenheimer Blue, a 14.62-carat vivid blue diamond sold at Christie’s Geneva for $57.5 million.

How Diamonds Get Color

Very rare .84-carat, kite-shaped, fancy red diamond, courtesy Swissdiam New York, LLC.

Let’s take a look at how diamonds get their color.  The colors in diamonds come about through trace elements when they are forming in the ground.

  • Yellow diamonds get their color from the presence of nitrogen.
  • Blue diamonds get their color from traces of boron.
  • Green diamonds get their color from natural radiation in the earth.
  • Pink and red diamonds are a bit of a mystery. Gemologists believe that they get their blushing shades from an anomaly in the internal structure of the gem as they are forming.

Many colored diamonds have modifying undertones to the stones, which shift the color and can change the value of the gem. For example, a diamond may be graded as purplish-pink. That means that the main body color of the stone is pink, but it has purple modifiers with pink the dominant color. It will look quite a bit different than an orangey-pink, which has an orange undertone to the pink.  Sometimes the blend of colors in a colored diamond is more balanced and then it will be given a name such as blue-green. Modifying colors may also change the value of a colored diamond. The grade that a colored diamond receives from a gemological laboratory can mean a price difference of many thousands of dollars.

“The modifying undertone colors, such as brown in yellow or pink is usually not good, or gray in blue is not great, for example,” explains Rima Farah, president Swissdiam New York LLC, a firm specializing in colored diamonds with offices in New York and Geneva. “You may get some green in a yellow diamond and people will like that neon color, or you may have some green in a blue. That is attractive and may add value. Some people want that pure color of one tone, but some don’t. Most people also don’t realize that when a color is a ‘pure’ shade it’s not what you necessarily expect. There are times when an undertone can make a color muddy and we don’t want that either. A modifying color may or may not add value, it’s not a hard scientific fact.”

Colored Diamond Grading

There is some important terminology to note when you are looking at colored diamonds. There are three factors for determining color:

  • Hue, which is the dominant color of the stone.
  • Tone is whether the color is light to dark.
  • Saturation of color which can be weak to strong.
Pink and yellow diamond ring features a 1.01-carat oval pink center stone with a 1.01-carat oval intense yellow side stone and a 1.03-carat intense yellow side stone with white diamond surround, courtesy, Swissdiam New York, LLC.

Next based on those three criteria, colored diamonds are once again divided into categories:

  • Fancy and Fancy Light: These stones are paler, softer shades of a color.
  • Fancy Vivid and Fancy Intense: These are the most coveted and desired because the color in the gem is balanced.
  • Fancy Deep: These diamonds are deeper in tone, but not too saturated with color.
  • Fancy Dark: These stones tend to have a dark body color and dark tone.

“These terms only define the color,” comments Farah. “An untrained eye might not see that a light pink diamond is pink, but in a fancy pink, they can see the color. It’s a matter of taste and whether or not someone wants more color, then they will like a vivid or intense color. When the color is too strong, the diamond loses sparkle and the color becomes dull.”

The Cut Factor

Yellow and white diamond ring features a 2-carat round fancy yellow center stone with yellow and white diamond accents, set in 18-karat white gold, courtesy Swissdiam New York, LLC.

Fancy colored diamonds are often also fancy shapes (any shape other than round) because they are cut to bring out the maximum color in the stone.

“Cut has a lot of impact on a colored diamond,” says Farah. “The cut determines whether or not the color is maximized. You can take a round colored diamond which may not have much color and turn it into a radiant or other fancy shape and that will increase the color.”

Farah makes one last, but very important point about purchasing a colored diamond. She notes that when white diamonds have a particular grade many people believe that they look pretty much the same, which is why they are comfortable buying a white diamond sight unseen based on the gemological report. Colored diamonds are different because everybody perceives color differently and because there is so much variation from stone to stone due to modifying colors.

“You can have three colored diamonds with the same information on each grading report,” concludes Farah. “But the stones are not the same. To the eye they will all look different, the value cannot be described by a piece of paper. You have to see the stone in person to really see it.”

Featured image (top of page): Ring features a 3.02-carat, oval intense yellow-green center stone, with yellow and pink diamond accent stones set in 18-karat white gold, courtesy Swissdiam New York, LLC.

Authored by Amber Michelle

The Legendary Argyle Mine

Argyle Diamond Mine Processing Plant, Photo Courtesy: Rio Tinto. Argyle Pink Diamond, Photo Courtesy: LJ West Diamonds.

Deep in the wilderness, in the east Kimberley region of Western Australia, the Aboriginal people pass down their history through oral storytelling. One of the stories, Barramundi Dreaming, is a mystical tale of how pink diamonds from the Argyle Diamond Mine got their color. According to folklore, three women were casting nets in the water to catch fish. In an effort to escape the nets, a barramundi fish jumped in the air and flew over the nets. In the process the fish dropped its scales in the water and on the rocks, which the legend says, turned into pink diamonds.

The Argyle diamond mine sits on land that belongs to the Miriuwong, Gidja, Malgnin and Wularr people who are the traditional custodians of this remote area. Diamonds were discovered in the region in 1979 and mining company Rio Tinto began operations at the Argyle Mine in 1983, leasing the land from its owners. The Argyle Pink Diamond Facility is located in Perth, Australia.

Surprise Discovery

During its 37-year lifespan, the mine produced some 865 million carats of rough diamonds. Most of the gems were lower quality brown or industrial diamonds. Then something unexpected and magical happened: Pink diamonds were discovered during production and through its lifespan the mine produced a steady supply of these gems in an extremely limited quantity. About one tenth of one percent of all of the diamonds found in the mine, were pink. Rarer still were red diamonds and even more rare – violet diamonds.

To put that in perspective, each year only about 50 to 60 pink diamonds were found in sizes above a half carat. Pink diamonds from the Argyle mine tend to range in size from 1 to 2-carats, with the very occasional gem reaching 3-carats. According to the miner, the gems are so rare that an entire year’s production of pink diamonds 1-carat and over would fit in the palm of your hand and it would take 15 years to collect enough pink diamonds to fill a champagne flute. Despite these strikingly small numbers, the Argyle mine produced 90 to 95 percent of the world’s pink diamonds. The remainder are found sporadically in Africa, Brazil and India.

Powerful Color

One of the attributes that sets Argyle pink diamonds apart from other pinks is their vibrant color. While they may be small, they have a powerful pop of color that ranges from soft powder puff pinks to vibrant fuchsias and magentas. According to the Gemological Institute of America (GIA), pink diamonds get their color from a distortion in the crystal structure of the gem as it is forming possibly due to the intense heat and pressure of being forced to the earth’s surface. The shift in the crystal structure causes the diamond to reflect light differently resulting in the pink colors that we see.

The rough stones were cut in the Argyle Perth facility by highly-skilled master cutters who carefully cajoled the best color and most sparkle out of each gem. The internal structure of pink diamonds makes them more challenging to cut and the artisans who worked on those stones had to be patient. Due to their internal structure it takes about four times longer to cut one of these precious pinks than it does a white diamond. From the time the diamond is found until the polishing is finished takes over a year.

Pink Diamond Tender

Once the diamonds were ready to sell, the stones were collected into a tender that travelled to major cities in the world to be viewed by about 150 dealers, retailers and collectors at invitation only events. The stones were sold by sealed bid and Rio Tinto never revealed the prices paid. What we do know is that pink diamonds can easily sell for $1 million to $2 million per carat and we could see prices take a leap in the next few years. In November 2020, the Argyle mine ceased production and with its closure the world has lost its one source that provided a steady supply of pink diamonds.

Rio Tinto has helped its Argyle employees make career transitions and it is working with the Traditional Owners and local stakeholders to dismantle the mine and rehabilitate the land, a process that is expected to take about five years. Once it is complete the land will be returned to the Traditional Owners as the custodians of Country to use for cattle grazing, tourism, cultural use and possibly small-scale agriculture.

Authored by Amber Michelle

The Allure of Vintage Diamonds

Bracelet Features Three Old European Cut Diamonds, Photo Courtesy: Global Gems

A mix of art and math, diamond cutting is a specialized skill that takes a rough rock from the ground and turns it into a dazzling object of desire. Through hundreds of years diamond cutting has evolved and changed as hand tools gave way to new technological innovations. The first diamonds were cut using hand tools and the cutter had to rely on his artistic ability and skill to cut the gems. This resulted in each diamond being slightly different with its own unique charm and personality.

Not to be confused with shape, cut is the arrangement of facets on a stone, while shape is its geometric form. Cut is very important to the appearance of a diamond. How facets are placed on a diamond impacts how much it will sparkle.

Early Diamond Cuts

Some of the first diamonds discovered in jewelry date back to the Roman era. These diamonds were in their natural rough state. Many years later the Table Cut was created and is widely considered to be the first diamond cut ever developed. The Table Cut took a rough diamond and cut off the tip of the stone, leaving a large, flat table-like area.

During the Renaissance period in the 1500s and 1600s some important diamond deposits were found in Brazil and India. Many of these diamonds made their way to Europe where skilled artisans began experimenting with ways to bring out the best attributes of these coveted gems.

These artistic experiments eventually led to the creation of the Rose Cut diamond. Developed in the 1500s, the cut got its name because it looks like a blossoming rose bud.  A Rose Cut diamond is dome shaped with a flat bottom. The dome is covered with triangular facets. Rose Cut diamonds have a lovely shimmering sparkle and a romantic, dreamy feeling.

Old Mine Cut Diamonds

While there were some intermediary steps that created new diamond cuts – such as the Mazarin that had 33 facets, the next cut to make a big impact in the diamond world was the Old Mine Cut, which first came on the scene in the 1700s. These diamond cuts follow the octahedral shape of the rough stone. Because each rough diamond is slightly different in form, Old Mine Cut diamonds can be found in round, square, cushion or rectangular shapes. They have 58 facets and are distinguished by a high crown – the top half of the diamond; small table, which is the large facet on top of the diamond and an open culet.  

When we look at a modern diamond, we are used to seeing the culet come to a point at the bottom of the stone. In an Old Mine Cut, there is no point at the bottom, instead there is a flat, open area. Since they were cut by hand, Old Mine diamond facet sizes and shapes will vary not only between stones, but also on the same stone itself.

Many Old Mine Cut diamonds were created before the advent of electricity. These diamonds were cut to be seen in candlelight and they are at their sparkling best when they are seen in that type of light, which is why they are sometimes called “candlelight diamonds”.  During the Georgian and Victorian eras, Old Mine Cut diamonds were at the height of their popularity.

Old European Cut

During the late 1800’s there was a new development in diamond faceting that led to the Old European Cut. Despite the name Old European, the cut was actually created in the United States by  business partners Henry Morse and Charles Field who established the first diamond cutting factory in the country. The diamonds were called Old European, because they were cut by people who had come to the United States from Europe.

The duo took cut parameters in a new direction focusing on smaller culets, better symmetry and smaller tables. This diamond cut became known as the Old European Cut and was much rounder in shape than its predecessor the Old Mine Cut. It also has a much smaller culet. Widely considered to be the precursor to the modern-day brilliant cut, the Old European Cut was popular in the first half of the 1900s.

Marcel Tolkowsky and the Ideal Cut

Enter mathematician and gemologist Marcel Tolkowsky. In 1919, Tolkowksy, who was working on his PhD at the University of London, did much of his research on “grinding” diamonds. His book, Diamond Design, grew out of his research and explained the best way to cut a diamond for maximum light return that creates the best sparkle, fire and brilliance. What he discovered is what we now know as the Ideal Cut. His research revealed that to coax out the best sparkle in the stone, a rough diamond needs to be cut into 58 perfectly proportioned facets. He also discovered that a diamond that was cut too deep or too shallow would lose light making it less sparkly. To this day, Tolkowsky’s Ideal Cut diamond is one of the most important modern diamond cuts.

As technology advanced and diamond cutting became more precise, diamonds began to have crisper facets and more defined lines and shapes. Yet despite these perfectly cut stones, vintage cut diamonds continue to capture the hearts and imagination of jewelry connoisseurs everywhere who love the handmade artisan feeling of these special treasures.

Authored by Amber Michelle

July Birthstone: Ruby

Above: Art Deco platinum, carved ruby and diamond bracelet, courtesy of Paul Fisher, Inc.

Celebrated present-day as the July birthstone, rubies have unceasingly enchanted and entranced humankind. From Greek mythology to Burmese tradition, the scarlet stone has served as a symbol for various societies, cultures, religions, and philosophies. Aptly referred to as the “King of Gems” in Sanskrit, rubies continue to be one of the most precious and coveted gemstones.

Ruby and sapphire are a variety of the mineral corundum, a crystalline form of aluminum oxide. Corundum is a 9 on the Mohs scale of mineral hardness, second only to diamond, making it a highly popular and wearable gemstone.

Ruby’s iconic red pigment comes from the presence of chromium in the compound: the higher the chromium concentrations, the stronger the red hue. Chromium can also cause fluorescence, which further increases the red color intensity. Rubies of the most saturated color, coupled with natural fluorescence, are referred to as “pigeon blood”. Untreated, gem-quality rubies with vibrant shades of red are especially rare and highly sought-after, asserting higher per-carat prices in the colored stone market.

The inimitable geology of Central Asia, Southeast Asia, and Mozambique are all sources for exceptional ruby crystals. For centuries, deposits in Burma (now Myanmar), especially those from Mogok in Northern Myanmar, produced incredible specimens of rubies, some with extraordinary “pigeon blood” vibrancy. In the late 2000s, gem-quality rubies were discovered in Mozambique, and the country has since become the world’s largest ruby producer. 

From armor augmentations to lavish ornamentation, craftsmen have employed the “King of Gems” for centuries, particularly as a mineral of choice for jewelry. Rubies have graced countless jewels through the various eras and design periods and continue to play an important role in the modern-day colored stone and jewelry fabrication markets.

Van Cleef & Arpels, platinum, ruby and diamond “margueritte” flower brooch, courtesy of J.&S.S. DeYoung, Inc.
Cartier 18K Gold and Ruby Clips, courtesy of G. Torroni S.A.

References

Giuliani, G. & Groat, L. (2019, Winter). Geology of corundum and emerald gem deposits. Gems & Gemology, 55(4), 464-489. GIA. https://www.gia.edu/doc/WN19-geology-of-corundum-and-emerald-gem-deposits.pdf

July Birthstone. GIA. https://www.gia.edu/birthstones/july-birthstones

May, L. (2016, November 23). 5 minutes with… A Burmese pigeon’s blood ruby ring. Christie’shttps://www.christies.com/features/5-minutes-with-A-Burmese-pigeons-blood-ruby-ring-7917-1.aspx

Rees, L. (2020, August 21). See the world’s rarest and most famous rubies. Galerie Magazinehttps://www.galeriemagazine.com/rubies-most-famous/

Ruby. SSEF. https://www.ssef.ch/ruby/

Ruby Care and Cleaning Guide. GIA. https://www.gia.edu/ruby-care-cleaning

Ruby Description. GIA. https://www.gia.edu/ruby-description

Ruby Quality Factors. GIA. https://www.gia.edu/ruby-quality-factor

Shor, R. & Weldon, R. (2009, Winter). Ruby and sapphire production and distribution: A quarter century of change. Gems & Gemology, 45(4), 236-259. GIA. https://www.gia.edu/doc/Ruby-and-Sapphire-Production-and-Distribution.pdf

Young, K. (2019, February 10). Rock stars: Diamonds may be a girl’s best friend, but blood-red rubies are a cut above other gemstones. CBS News. https://www.cbsnews.com/news/rubies-the-real-rock-stars/