All Things Diamonds, Gemstones and Jewelry

[finessediamonds]

Diamond Color Treatments Explained

An important part of understanding colored diamonds is knowing the difference between natural and treated because there is a HUGE difference. We break it all down below so read on and learn about the 3 most common diamond color treatments.

(This article is part of our LinkedIn series “2016:The Year of Color”)

Not all colored diamonds are rare. Only those that are created by Mother Nature carry prestige and value with them. Color-treated diamonds are essentially low-quality rocks with a makeover. Today, there are three commonly used types of treatment that produce colored diamonds – coating, HPHT and irradiation. These are all acceptable as long as the treatment is disclosed. It is completely unethical to present a treated stone as natural. To ensure a diamond has natural color, always look for “origin” on the GIA certificate.

Coating –

A less desirable diamond can be covered with a thin layer of chemical material to give it a new color. The coating can crack or chip, revealing the true color underneath. Sometimes, so it is less noticeable, the coating will be applied only to the girdle or pavilion of the stone.

HPHT –

A diamond can be exposed to high-pressure and high-temperature in a lab, similar to how diamonds form naturally, to permanently enhance their color. The process can be used on low color diamonds to make them colorless, pink, blue, green, yellowish green, or yellow (according to GIA.)

Irradiation –

A diamond can be exposed to radiation in a lab to permanently alter the stone’s crystal lattice structure, presenting a new color. Irradiation alone produces green diamonds but when combined with high heat, labs can produce blue, yellow, brown and black diamonds too.

Since diamonds can also be exposed to natural radiation, this type of treatment is practically undetectable without proper equipment. The only way to be absolutely certain the diamond is natural is to send it to a trusted lab for grading. However, irradiated diamonds will often display orange fluorescence and may have a higher concentration of color near the culet.

Irradiated green diamond 

and a natural green diamond

If you have any questions regarding diamond color treatments, please ask!

[finessediamonds]

The 4Cs of Natural Colored Diamonds

Colored diamonds are special. They’re rare and unique. Learn how the 4Cs differ from traditional colorless diamonds below.

(This article is part of our LinkedIn series “2016:The Year of Color”)

We all know what the 4Cs stand for- Cut, Color, Clarity, and Carat (weight). The jewelry industry has done a great job educating consumers about each one so they can make an informed purchase decision. It’s also true that colorless or “white” diamonds are valued according to these 4 criteria, among a few others. While colored diamonds are also gauged by the same qualities, their importance is much different.

Color

The king of all the Cs. Natural colored diamonds are valuable because of their color, so this is without a doubt the most important.  GIA incorporates three elements into its fancy color grading system: hue, saturation and tone. Hue is simply the color of the diamond -yellow, pink, brown, etc. There are 27 individual hues in GIA’s hue circle.

These hues vary in tone, which is how light or dark the color of the diamond appears.

Saturation is the strength of color in a diamond. There are nine distinct intensity levels in GIA’s natural color grading system: Faint, Very Light, Light, Fancy Light, Fancy, Fancy Intense, Fancy Dark, Fancy Deep, and Fancy Vivid. The stronger the color in a diamond, the rare and therefore, valuable. Fancy Vivid is the rarest, most valuable and most desired saturation level for colored diamonds because it combines the perfect tone and saturation, allowing the color to really pop. Fancy Intense and Fancy Deep are usually second to Vivid because the color is rich without being too light or dark.

Colored diamonds will frequently have more than one hue and can actually have up to three modifying colors. Sometimes, when two colors are dominant, a ‘split’ color grade is given, e.g. Fancy Green-Yellow. In other cases, the dominant color can be modified by one or a few additional colors (aka: overtones), e.g. Fancy Deep Brownish Greenish Yellow. In any case, the final color named is always the most prominent color. Generally, a colored diamond is most valuable when it has just one hue because they are found less often in nature.

Some colors like brown and yellow are quite common, especially compared to other colors like purple, green, orange and red. Defining rarity and value though, is not so linear. Even those who have been in the business for decades will disagree on the rarest color. However, we do know that the colors discovered less frequently during mining, that are most popular among collectors and with strong, pure color are absolutely the most coveted.

"In my experience as the color gets more and more rare the other C's fade in importance. As one gets to the truly exceptionally rare colors the other factors matter very little. " –Tom Gelb (Gelb Gemological Consulting)

Cut

Shape and cut play a big role in a diamond’s color. Since color determines price first and foremost, diamonds are cut to retain the most color, with less regard for clarity, symmetry, proportions, etc. In fact, many colored diamonds have deep pavilions because it causes light to travel farther, often presenting a richer color to the eye.

While the shape is different from the cut grade, it also plays a large role in color. The round shape for example, was created to enhance the scintillation in white diamonds, helping them appear whiter. For this reason, very few rough colored diamonds are saturated enough to be cut into rounds. To maximize color, many are cut into fancy shapes such as radiants, pears and ovals. Some fancy shapes even provide a higher yield from the rough, resulting in a better carat weight, and a more desirable diamond.

Clarity

Most colored diamonds fall somewhere in the SI-I clarity range. But even those with low clarity grades can still be highly desired if they show beautiful color. Quite often, colored diamonds have “white” inclusions like feathers and clouds, and are masked by the stones color. However, like in colorless diamonds, black inclusions and those that threaten the integrity of the stone can significantly lower value. Natural colored diamonds can also display color “graining” (bands or lines of color) which is considered an inclusion.

Color Graining Under Magnification (Photo Credit: GIA)

Natural colored diamonds with VS clarity or better are exceedingly rare. To illustrate this point better, of 19,530 natural colored diamonds (I did not include black, white, brown, yellow or grey) currently listed on Rapnet, only 23.5% are VS or better, with almost exactly half of those graded VS2.

Carat

Of course, larger diamonds are more valuable than smaller ones because they are rarer and more desirable. Natural colored diamonds are already much more scarce than white diamonds (only 1 in 10,000 diamonds mined result in fancy color), but depending on color, even those over just one carat can be quite a find.

A 36 carat natural fancy yellow diamond, VS1

Without a doubt, color is the most important factor when determining the value of a colored diamond. Carat weight plays a large role too because so few large colored diamonds exist. Clarity and cut matter much less, however, when excellence in either or both combine, the value will undoubtedly rise.

[finessediamonds]

Natural Chameleon Diamonds

Colored diamonds are rare, but these unique gems can actually change color! The most interesting part? Scientists haven’t been able to determine exactly what causes this phenomenon. Learn more about these wild jewels and read on. 

Let's Get Fancy: Chameleon Diamonds

(This article is part of our LinkedIn series “2016:The Year of Color”)

Chameleon diamonds are among some of the most fascinating gems in existence and a standout among all fancy colored diamonds for their distinctive ability to change color. They submit to a short-lived color change when subject to one of two environmental stimuli: (1) a temperature that reaches 140°C or (2) absence of light for an extended period of time. Chameleon diamonds that change color based on temperature are “thermochromic” while those that are sensitive to an absence of light are “photochromic.” According to research conducted by GIA in 2005, exposure to heat tends to yield a more obvious change in color than a lengthy time spent in the dark.

Color

Chameleon diamonds generally change from an olive green color (typically graded as greyish yellowish green or greyish greenish yellow) to an unstable color of a more intense brownish or orangey yellow shade and are labeled as “classic” chameleons.  Some chameleon diamonds have a light yellow color that transforms into a more intense greenish yellow and are known as “reverse” -although GIA does not denote the term “chameleon” to these diamonds on their certificates. Reverse chameleon diamonds can apparently only change color only when heated.

Some chameleon diamonds exhibit a steady green hue similar to conventional natural green diamonds. While we know that conventional green diamonds derive their color from radiation, it is not yet absolutely clear what gives chameleon diamonds their color. A hydrogen-related defect appears to be the main cause.

Secondary Color Modifiers

Chameleon diamonds are typically green or yellow diamonds that have secondary colors of grey, yellow (if the main color is green), green (if the main color is yellow) and/or brown.

Intensity

Chameleon diamonds are assessed according to their color intensity - a combination of saturation and tone.  They can be found with the following intensities:

Fluorescence

It is normal for chameleon diamonds to display fluorescence. Chameleon diamonds characteristically exhibit a medium to strong yellow fluorescence.

Clarity

Chameleon diamond clarity generally ranges from VS1 to I1. Clarity is of secondary importance in chameleon diamonds because they are prized first and foremost for their color, particularly a main body color that is green.

Shape

Chameleon diamonds can be found in virtually all shapes. Since they tend to have a darker tone, the round cut won’t necessarily desaturate the color, making them more common than in other rare colors like blue or orange.

Value

Although chameleon diamonds are some of the rarest diamonds to exist, they tend to be more affordably priced compared to other diamonds of the rarest degree, such as natural purples and blues, presumably because demand is not as high.

The value of a chameleon diamond will depend mostly on main body color (green is generally the most desired) and intensity of the color change. Less common shapes, such as the emerald cut, can have a big impact on value as well.

History

The first documentation of color changing diamonds surfaced in 1943 when, according to the GIA Diamond Dictionary, Peter Kaplan, of Peter K. Kaplan Inc., noticed a diamond changing to a darker color during the polishing process. The heat of the wheel was altering the color before his eyes. The diamond, eventually graded a light yellow-green, was sold to a customer who returned it after pulling it from storage and noticing the change in color, believing she had been duped.

At 31.31 carats, the Chopard Chameleon (above) is the largest to date and is nearly flawless. The color changing diamond was mounted in the center of a ring accented with small yellow diamonds in a pave setting. Caroline Gruosi-Scheufele designed the ring and it was unveiled at Baselworld in 2008.

You have to see this phenomenon for yourself. It is truly amazing!

[finessediamonds]

Natural Red Diamonds

Many experts agree -they’re the rarest diamond color on the planet. Although a few have been discovered in the past few years, there are still just a handful on the market.

Let’s Get Fancy: Red Diamonds

(This article is part of our LinkedIn series “2016:The Year of Color”)

Natural red diamonds are considered by many to be the most elusive and fascinating of all colored diamonds. They are so scarce that GIA did not issue a single grading report for a “Fancy Red” diamond from 1957 to 1987. Not surprisingly, due to the lack of fancy red diamonds on the market, this diamond color commands some of the highest prices per carat. Most red diamonds come from the Argyle mine in Australia but other producers include Russia, Brazil and India.

Color

The source of color in red diamonds is believed to be, like in pink diamonds, structural defects caused by small movements occurring in the atoms, a process referred to as ‘plastic deformation.’ The structural defects materialize as a series of tightly positioned grain lines that present red color.

Intensity

Unlike most other colored diamonds, natural fancy red diamonds cannot receive color intensity grades. Red diamonds essentially exist at the end of the pink spectrum. When a pink diamond’s color is so saturated that it can no longer be considered a deep or dark pink, it will appear red. So fundamentally, a "light red" cannot exist because it would actually appear pink. And a diamond that appears red with a darker tone will then fall into the "brownish" red category.

Secondary Color Modifiers

Natural red diamonds are quite rare in general but they are exceedingly rare when they exist as pure red, without any modifying colors. However, they can be found paired with purple, orange and brown. Red diamonds are not modified by pink because as discussed above, pink is just a lighter shade of red.

Clarity

Natural red diamonds tend to involuntarily sacrifice flawlessness for their coveted color –it’s just the nature of the material. They can generally be found in the VS1 to SI2 range. They seldom stray outside this range, and it is especially uncommon for one to have a grade higher than VS1.

Shape

Most red diamonds are cut into fancy shapes such as radiants and ovals because these are best at displaying red color. The round shape tends to produce lower color saturation so a round red diamond is extremely hard to come by and since they are so uncommon, they often command the highest prices.

Value

More often than not, red diamonds, no matter how small, carry six-digit figures per carat and even seven-digit figures for the most desirable specimens. Pure fancy reds and rare cuts such as rounds and emeralds are the most valuable on today’s market.

Typically, color, size and clarity – in that order – are the biggest factors for determining the value of a red diamond.

History

Red diamonds are so rare that they weren’t really a topic of discussion until the late 1980s. Red diamonds gained some fame in April 1987 when a Christie’s auction featured a 0.95 carat round brilliant cut Fancy Purplish Red diamond (known as the Hancock Red) and it fetched a record-breaking $927,000 per carat. Since then the interest surrounding red diamonds has increased with announcements of new red diamond discoveries.

The Hancock Red Diamond (Photo courtesy of GIA)

In 1998, the New-York based William Goldberg Co. cut and sold the largest natural red diamond to be graded by the GIA to date, a 5.11 carat shield-shaped Fancy Red diamond of Brazilian origin. It would later become known as the Moussaieff Red and one of the key attractions of the Smithsonian Institution’s “The Splendor of Diamonds” exhibit.

The Moussaieff Red Diamond (Photo courtesy of GIA)

[finessediamonds]

Natural Black Diamonds

They’re mysteriously beautiful, but where do they come from? Keep reading to learn more about the diamonds that are “out of this world.”

Let’s Get Fancy: Black Diamonds

(This article is part of our LinkedIn series “2016:The Year of Color”)

Although the public may not yet be aware, truly natural black diamonds are among the rarest colored diamonds and often have a high price per carat. Most black diamonds on the market are treated and far less expensive. Since so much jewelry we see today features the treated black stones with budget prices, natural ones get far less attention. They are also quite different from the rest of colored diamonds in pretty much all other aspects.

Color

Natural black diamonds get their color from a large amount of dark inclusions that are evenly distributed throughout the stone, resulting in an overall black look. Unlike colorless diamonds and other natural colored diamonds, black diamonds absorb, rather than reflect and refract, light. This unique property gives them an opaque appearance. Brilliance and light performance are noticeably absent in black diamonds but instead they have a mysteriously beautiful and glossy surface.

Because of the opaque nature of black diamonds, the usual features of colored diamonds, such as color intensity, secondary modifiers, tone, clarity and fluorescence, do not apply. GIA grades natural black diamonds only for shape and cutting style, measurements, weight, color origin, grade and distribution. These qualities are detailed in a specific type of report called a “Colored Diamond Identification and Origin Report”.

Shape

Since color intensity is irrelevant to the appearance and valuation of natural black diamonds, they can be cut into all shapes, including the round.

Value

Although natural black diamonds sell for a higher price than their treated counterparts, they cost noticeably less than most natural fancy colored diamonds of comparable weight. Some in the industry expect the value of these ebony gems to rise in the future as consumers become more aware of the difference between the natural and treated stones.

History

Black diamonds are probably the least understood of all colored diamonds. Natural black diamonds, also referred to as “carbonados”, have very little in common, chemically and physically, with other colored diamonds. Brazilians gave them the nickname after the Portuguese word meaning carbonized or burnt since black diamonds are dark and porous like charcoal.

The large amount of hydrogen and nitrogen in their chemical composition and the fact that they are roughly 3.8 billion years old (far older than any other diamonds on Earth) has led scientists to believe that black diamonds actually came from a supernova and landed on earth via a meteorite! To back up this theory, they can be found only in alluvial deposits in Brazil and the Central African Republic. And unlike other diamonds, they do not occupy any kimberlite pipe.

Natural black diamonds are so hard, they can be cut only by other black diamonds. They are polycrystalline, or made up of millions of small crystals joined as one unit, whereas other diamonds are a single crystal that “cleaves”.

The Spirit of de Grisogono Diamond

312.24 carats - The world's largest black diamond

The Black Orlov

67.50 carats - also referred to as the Eye of Brahma diamond

[finessediamonds]

Natural Purple Diamonds

Natural colored diamonds are rare, but purple diamonds with pure color are among the rarest and most stunning. Learn more about this crazy color below.

Let’s Get Fancy: Purple Diamonds 

(This article is part of our LinkedIn series “2016:The Year of Color”)

Natural purple diamonds without any color modifiers are nearly as rare as red diamonds and are seldom found in sizes larger than five carats. It is much more common for purple diamonds to weigh no more than two carats, and more often than not, paired with secondary color modifiers.  So if you see a pure purple diamond of a nice size, you are beholding something truly rare and valuable.

Color

Natural purple diamonds get their color from what is known as “crystal distortion”, or mutation of the atomic lattice, just like pink and red diamonds. However, the precise composition of such defects is still not entirely clear and is still being researched. A distinguishing characteristic of natural purple diamonds is what we call “color graining”, or to be more scientific, the pronounced presence of parallel deformation lamellae, where coloration is concentrated. This means the purple color we see in a diamond may vary in strength based on the angle when being viewed.

Intensity

Purple diamonds are graded based on intensity of color, or a combination of saturation and tone.  The following describe purple diamond intensities:

The further along this spectrum you go, the richer the color, and the higher the value. For example, a Fancy Vivid Purple diamond will be worth more than a Fancy Purple diamond.

Secondary Color Modifiers

Purple diamonds can be modified by pink, red, grey and brown. Although, it is more common for purple to be found as a secondary color modifier, such as a diamond graded Fancy Purplish Pink, than for it to be the dominant color in a diamond.

Pure purple diamonds with very saturated color and those that contain another rare color, such as Fancy Reddish Purple are among the most sought after and valuable.  

Fluorescence

Natural purple diamonds do not typically have fluorescence but when they do, the resulting color under UV light is usually very weak - weak yellow.  

Clarity

Natural purple diamonds are most often included and generally fall in the SI1 to I2 range. Dark inclusions and clouds are quite common. Purple diamonds with clarity grades of VS2 or better are rarer and command much higher prices.

Shape

Natural purple diamonds can be found in virtually all shapes. Unlike other colored diamonds, purple diamonds tend to have darker tones so they can sometimes be cut into the round brilliant shape without sacrificing color saturation. Keep in mind though, purple diamonds are so scarce that a round will still be very hard to come by.

Value

A colored diamond’s worth is determined first and foremost by its color.

Natural fancy purple diamonds are exceedingly rare and valuable. They are perhaps second only to natural red diamonds. The most expensive of all purple diamonds are those with uniformly purple color and without any color modifiers. However, as purple is arguably outdone by red as the rarest diamond color, one allowance can be made regarding secondary colors: a purple diamond that is modified by red is extremely valuable and will likely fetch a similar price per carat to pure purple diamonds.

History

Fancy purple diamonds are mined in Siberia (Russia), Australia, and more recently, Quebec, Canada. Purple diamonds from Siberia are mostly pale in color, but occasionally, diamonds with deeper color are mined.  Overall though, only 1% of all diamonds from Siberian mines are purple, showing just how rare they really are.

The Royal Purple Heart

The largest Fancy Vivid Purple diamond known to exist, 7.34 carats, I1

[finessediamonds]

Natural Blue Diamonds

We’ve seen blue diamonds fetch some insane prices at auction recently. (Hello, $48.4 million Blue Moon!) If you want to know more about why these gems are so collectible, read on.

Let’s Get Fancy: Blue Diamonds

(This article is part of our LinkedIn series “2016:The Year of Color”)

Natural blue diamonds are among the rarest of all colored diamonds. They account for less than 0.1% of the total diamond yield from the Cullinan (formerly known as the Premier) mine in South Africa – the mine responsible for producing the most blue diamonds for the market today.

They first originated from the Golconda region of India during the 17th century, but production stopped there centuries ago.

Color

Most natural blue diamonds are identified as type IIb.  Type I diamonds contain at least some nitrogen whereas type II diamonds do not. To break it down further, type IIa diamonds have neither nitrogen nor boron while type IIb do not have nitrogen but do have boron. (To learn more about diamond types, check out this article from Rapnet.)

Boron happens to be the element that gives blue diamonds their color, so the greater the amount of boron in a blue diamond, the richer the color will appear.

Intensity

Blue diamonds, like all colored diamonds, are assessed according to intensity of color, or a combination of tone and saturation.

The following describe blue diamond intensities:

The further along this spectrum you go, the deeper the color will appear and the more intense a diamond’s color, the more it will be worth.

Secondary Color Modifiers

Colored diamonds are generally rare when they exist as one color without any additional modifying colors. However, blue diamonds modified by other rare colors like green or violet can be quite valuable, especially in higher color grades like vivid or deep. A blue diamond with a grey modifier is considered less valuable on today’s market, as they are a bit easier to come by.  

Clarity

Unlike the majority of colored diamonds, fancy blue diamonds frequently have high clarities. According to a report from G&G, (an oldie, but goodie) the high clarity grades are related to the diamond type, not the color specifically.

Shape

In natural colored diamonds, a round cut may make the color appear fainter, whereas a fancy shape, will maximize color saturation. That’s why we most often see radiant, pear, cushion, etc. shaped blue diamonds.

Value

Blue diamonds have historically been among the rarest of all colored diamonds. Their extreme rarity thus makes them highly prized. The larger the size and the more saturated the color, the more valuable a blue diamond will be. Pair these factors with a rare round shape and watch the price skyrocket.

Famous Blue Diamonds

The hope diamond is a 45.52 carat Fancy Dark Greyish Blue diamond arguably the most famous blue diamond on Earth. It is now on display at the Smithsonian in Washington, D.C. To learn more about it, visit their site for a full history.

[finessediamonds]

Natural Orange Diamonds

They’re bright, they’re pretty and boy are they rare! Pure orange diamonds are so hard to come by that out of thousands of colored diamonds, our resident writer (yours truly) has never even held one. 

Read more about these fascinating gems below.

Let’s Get Fancy: Orange Diamonds

(This article is part of our LinkedIn series “2016:The Year of Color”)

A pure natural orange diamond is truly rare. The majority of orange diamonds are type Ib, which make up less than 0.1% of all diamonds, putting them among the rarest kind of diamonds in existence. (If you aren’t familiar with diamond types,read this GIA article.)

Color

Fancy orange diamonds contain atoms of nitrogen uniformly distributed in the crystal lattice structure that absorb blue and yellow light, ultimately resulting in orange color. The depth of color seen in a diamond is known as the “intensity” - the combination of tone and saturation. Differences in color appearance are credited to tone, which is the particular point that a diamond falls in the light to dark spectrum.

Intensity

As with other natural colored diamonds, the further along this spectrum you go, the richer the color will appear. And of course, since more saturated stones are rarest, the more intense a diamond’s color, the more it will be worth.

Secondary Color Modifiers

Fancy orange diamonds are most commonly paired with secondary color modifiers, aka “overtones”, of brown, yellow, pink or the very rare red.

A color diamond is generally rare when it exists as one color without any additional modifying colors. Sometimes though, orange diamonds can experience even greater rarity and value, like when orange is combined with equally, if not more, rare colors such as red or pink. A “fancy reddish orange” of substantial intensity is often more valuable than an orange diamond in a comparable saturation.

Fluorescence

Fluorescence is a natural phenomenon that affects many diamonds. If a diamond exibits fluorescence, the diamond will glow when exposed to UV light. Fluorescence most commonly appears as a blue color but can be encountered in other colors. Yellow fluorescence in an orange diamond can impart a golden cast and make the color appear softer. The way fluorescence affects a stone’s appearance is entirely subjective.

Clarity

Majority of natural orange diamonds have clarities that fall within the VS1 to I1 range. For those in the SI1-I1 assortment, the liveliness of their color is usually able to mask even significant inclusions (an added benefit of color!) And as with other colored diamonds, because of the acknowledged rarity and value of orange diamonds, their clarity is far less important compared to color and intensity.

Shape

Most colored diamonds are cut into fancy shapes such as radiants, cushions, pears, etc. to maximize the appearance of color. Since round cuts tend to produce lower color saturation, only rough with very strong color can be cut in the traditional round brilliant shape. Since orange diamonds are already very rare, finding one with enough color saturation to be round, is extremely uncommon.

Value

A colored diamond’s value is determined first and foremost by its color. The more intense the color, the more it will be worth. Pure orange diamonds are particularly rare and command prices that are comparable to some pink and blue diamonds. However, natural orange diamonds are commonly found with modifying colors of brown and yellow and these are typically less expensive. On the other hand, orange diamonds combined with rare and highly prized modifying colors of red and pink, will often see a spike in price.  

History

Fancy orange diamonds can be traced to Australia’s Argyle mine and the mines of South Africa. Compared to more popular fancy colors such as yellow and pink, the history of orange diamonds has not been examined in depth.

The Pumpkin Diamond is a 5.54 ct, type IIa cushion cut Fancy Vivid Orange diamond from South Africa and is one of the largest of its kind to ever be graded by the GIA.

The Orange is currently the largest vivid orange diamond in the world. It is a 14.82 ct, type IIa, VS1 Fancy Vivid Orange pear shape that achieved the highest price per-carat for a colored diamond, as well as any fancy vivid orange diamond, at Christie’s Geneva auction in November 2013 when it fetched $2.4 million per carat. (It has since been dethroned by this diamond!)

[finessediamonds]

Natural Green Diamonds

Green diamonds have quite an interesting story! They aren’t just rare and valuable-  they aren’t like any other diamonds. Read on to see what gives these funky gems their rare color.

Let’s Get Fancy: Green Diamonds 

(This article is part of our LinkedIn series “2016:The Year of Color”)

Color

Natural green diamonds are exceptionally rare and valuable. They owe their color to radiation exposure that occurs at or near the Earth's surface, after the diamond has formed and traveled up the volcanic pipe.  Only those parts of the stone that are subjected to radiation will show green color. As rare as green diamonds are, a diamond with uniform green color is categorically unusual.

Green diamonds can be grouped into two classes: those which possess natural body color, and those commonly called “skin stones”, where the source of green color is caused by remnants of radiation marked on the outside of a diamond. Most natural green diamonds are skin stones, making body color green diamonds even more rare and valuable.

A green diamond’s color is determined by three factors: (1) the type of radiation the diamond has been subjected to; (2) how long the exposure lasted; and (3) size.

Alpha radiation tends to affect only the surface of the diamonds, resulting in skin stones. Beta and gamma radiation, on the other hand, will penetrate the stone more deeply, thus producing diamonds with much greener color and uniform color distribution. Natural green diamonds that come from beta and gamma radiation are quite special – incidents of this take place less than 0.1% of the time.

Intensity

Colored diamonds are evaluated according to intensity of color, or a combination of saturation and tone.  The following describe green diamond intensities - Light Green, Fancy Light Green, Fancy Green, Fancy Intense Green, Fancy Dark Green, Fancy Deep Green, and Fancy Vivid Green.

Secondary Color Modifiers

Green diamonds can be found paired with yellow, gray and blue. Diamonds that are modified by colors that are less rare, such as yellow and grey are generally less valuable when compared to those combined with more rare colors like blue. A “fancy blue-green” of considerable saturation will command a very high price as this color combination is among the rarest.

Fluorescence

It is somewhat common for green diamonds to have fluorescence. They tend to display fluorescence in one of the following varieties: medium to strong blue, strong green, strong yellow and strong white.

Clarity

A green diamond with a clarity grade of VS-Flawless is remarkably rare. Although, a green diamond that falls on the lower end of the clarity scale is still valuable and rare as long as any major inclusions do not detract from the color and overall appearance of the stone.

Shape

The round shape tends to produce lower color saturation so most colored diamonds cut into fancy shapes such as radiants, cushions, etc. This makes a round green diamond extremely rare and highly prized.

Value

Natural fancy green diamonds have very high value. The more intense a diamond’s color saturation, the more it will be worth. That said, apart from very saturated pure greens, stones that are a split grade containing another truly rare color of highest saturation, such as Fancy Vivid Blue-Green, are among the most desirable and valuable types of natural green diamonds. Of course, as size increases, so, too, will their price per carat.

History

Natural green diamonds originate from the mines of Africa and South America including those in Brazil, Guyana and Venezuela. The single largest challenge confronting gemologists today is establishing a precise way to tell the difference between a natural green diamond from a treated one. Green diamonds can be irradiated in a laboratory environment making it nearly impossible to differentiate natural from treated stones. Oftentimes, during the cutting and polishing process, a small part of the skin is left on a green diamond so it can be identified as natural.

The most famous and the largest known green diamond that exemplifies green body color is the historic 40.70 carat Dresden Green.

Green diamonds are among my personal favorites. What do you think about them?

[finessediamonds]

Natural Brown Diamonds

Brown may be the most controversial diamond color to exist. They’re abundant, affordable and backed by two of the most genius marketing campaigns to ever hit the diamond industry. Keep reading to learn more about this contentious color.

Let’s Get Fancy: Brown Diamonds 

(This article is part of our LinkedIn series “2016:The Year of Color”)

Terminology

Brown. Not such an attractive color, right? A lot of unpleasant things are brown. Dirt, bugs, rats, and well….you know.

So when a few smart people in the diamond industry realized that there was a plethora of brown diamonds just begging to be cool, they decided to change the association our minds make to things wayyy more appealing. So now brown diamonds have many, many aliases. Champagne, cognac, cinnamon, café, mocha, and chocolate. (Did I miss any?)

It all started when The Argyle mine in Australia found that roughly 80% of their output consisted of brown diamonds back in the 1980s. To ensure success, they orchestrated a large-scale advertising campaign with the objective of changing the perception of brown diamonds in the marketplace and to this day use ‘champagne’ and ‘cognac’ as the designation for brown diamonds.

Then came Le Vian. They started the “Chocolate Diamonds®” brand in the year 2000 in an effort to mass market brown diamonds and transform them into something delicious and desirable. In 2009 the US Office of Patent and Trademarks, granted Le Vian the registered trademark for Chocolate Diamonds® and it now stands in over 100 countries.

Color

Natural brown diamonds, like pink diamonds, owe their color to a molecular level defects in their crystal lattice known as ‘plastic deformation’.

Brown diamonds can be given GIA grades of Fancy Light, Fancy and Fancy Dark, while fully saturated browns are graded as Fancy Deep. Since brown is an expression of darkness of tone in hues that skew warm and GIA defines fancy color diamonds that are ‘Intense’ and ‘Vivid’ as having high saturation and lightness of tone, any diamond that has brown cannot be graded Intense or Vivid.

It is also worth noting that because brown diamonds comprise a wide-ranging set of hues, they tend to show the greatest differences in their color presentation compared to all other fancy color diamonds. Additionally, the more intense a diamond’s color saturation, the more it will be worth.

Intensity

Natural fancy brown diamonds are assessed according to intensity of color, or a combination of saturation and tone.  The following describe brown diamond intensities:

Fancy Light Brown, Fancy Brown, Fancy Dark Brown, and Fancy Deep Brown

Secondary Color Modifiers

Brown diamonds can be found mixed with yellow, orange and pink overtone colors. The secondary colors will be most apparent as the saturation of overall color increases.

A colored diamond is generally rare when it exists as one color without any modifying colors.  But when a brown diamond is modified by a much rarer color, like pink or orange, resulting in a Fancy Pink-Brown or Fancy Orange-Brown grade, it will be more valuable than a Fancy Brown diamond.

Shape

Brown diamonds can be found in all shapes, even the round brilliant cut, which is not common in other fancy colored diamonds. In the case of brown diamonds, a round cut does not necessarily desaturate color, as they usually have darker tones than other color diamonds.

Value

Because the bulk of diamond output from the Argyle and other mines is brown, they are found in greatest abundance compared to all diamonds. In contrast to the much rarer pink, blue, green and red, brown diamonds are much easier to obtain, making them the most affordable.

History

Brown diamonds originate primarily from the Argyle mine as well as South Africa and Russia. The function of low quality brown diamonds for many years was industrial. However, fancy brown diamonds as graded by GIA are considered gem quality, whereas those used for industrial purposes are not.

The industry has opinions that are both strong and varied when it comes to brown diamonds. So where do you stand?

[finessediamonds]

Natural Pink Diamonds

The second article in our series on colored diamonds focuses on the ever popular pink diamonds. They’re not just pretty, they’re quite valuable and 2015 brought us some incredible record breaking prices at auction. Keep reading for all the facts about this fancy color.

Let’s Get Fancy: Pink Diamonds

(This article is part of our LinkedIn series “2016:The Year of Color”)

Pink diamonds are extremely rare. How rare? Well, consider this - Pink diamonds have been found in very limited supply from just a few mines around the world. In the 17th and 18th centuries, pink diamonds were discovered in the Golconda region of India and the Minas Gerais region of Brazil. But since the late 1980s, the Argyle mine in Northwestern Australia has become the leading producer of natural pink diamonds, generating over 90% of the world’s supply, and is the sole source of the most rare and significant pinks available today. Out of the over 30 million carats of rough mined at Argyle each year, less than 10,000 carats are pink, and less than 1,000 carats weighed more than 0.20ct in their rough form!

Color

Unlike other natural fancy colored diamonds (which owe their hues to the presence of trace elements) scientists believe a fancy pink diamond gets its color thanks to an atomic level lattice defect known as ‘plastic deformation’.

The Pink Diamond Scale of color intensity is based on a combination of saturation and tone. The following describe pink diamond color intensities:

Color intensity and carat weight have the biggest effect on a fancy color diamond’s price, and this is certainly true for pinks. The more intense a diamond’s color, the more it will be worth. For example, a Fancy Intense Pink diamond will be worth more than a Fancy Light Pink or Fancy Pink of similar quality.

- Color Modifiers

In the case of pinks, secondary modifying colors such as orange, brown, and purple can be present. Sometimes the presence of these colors is so subtle they won’t even register on the naked eye. Stones with secondary color modifiers that are also rare, such as purple or orange, tend to be collectors’ items and sell for higher prices whereas those with a brown modifier are often more affordable.  A fancy pink diamond with no overtone is extremely rare, especially those with strong color. However, certain exceptional stones such as the Argyle Mystra, a 2.02ct Fancy Vivid Purplish Pink round is the ideal combination of carat weight, intensity, cut (round is a very rare shape for a natural colored diamond) and purplish overtone make this diamond one of the rarest pink diamonds in existence.

Clarity

Fancy Pink diamonds in general tend to be included, yet because of their overall rarity, clarity is a much smaller factor in their valuation. This is especially true when compared to more common colors like, yellow or brown. (If you missed last week’s installment on yellow, check it out here!) According to GIA, less than 7% of all pink diamonds are given a clarity grade of Flawless or Internally Flawless, and almost half are either Slightly Included or Included.

Shape

The round shape is reserved for rough with strong color saturation since the cut reflects more white light and can make the color appear fainter, whereas a fancy shape will maximize color saturation. Because of this, pink diamonds, like other colors, are generally cut into fancy shapes such as cushions, radiants, pears, etc. This means that round pink diamonds often command much higher prices since they are harder to find.

Value

Pink is one of the rarest colors in the natural colored diamond world and is prized by consumers and collectors alike. Demand paired with constraints on supply (the Argyle mine is reported to shut down by 2020), has forced the price of pink diamonds to steadily climb. Over the years, many have fetched millions of dollars per carat at auction. This is a trend that doesn’t show signs of stopping anytime soon.

Comments and questions are always welcome - Let's chat!

[finessediamonds]

Natural Yellow Diamonds

This year we are celebrating color more than ever so we’re kicking off 2016 with an educational series about natural colored diamonds.  Each week we will feature a new color and share all the latest information, including: color grading, history, value and more.

Let's Get Fancy: Yellow Diamonds

(This article is part of our LinkedIn series “2016:The Year of Color”) 

Terminology

Fancy yellow diamonds begin where the colorless D-Z grading scale ends. Although some stones on the colorless scale may appear a bit yellow, they are not considered “Fancy” Yellow. K-M (Faint Yellow), N-R (Very Light Yellow) and S-Z (Light Yellow) stones are referred to as “Cape” colors. The term comes to us from the very beginning. Yellow diamonds were first found in the Cape Province of South Africa in the 1860s, and since the stones found there had light yellow tones, the name stuck. “Canary” is essentially a slang term used by many as an alternative to “yellow” and has a long history too. (I suggest you read this article for all the deets.)

Color

Like many other fancy colors, yellow diamonds get their color thanks to the presence of a trace element in their atomic structure. In this case, the element is nitrogen. The more nitrogen in the diamond, the more saturated the yellow color will appear.

The Yellow Diamond Scale of color intensity is based on a combination of saturation and tone. The following describe yellow diamond color intensities:

The further along the scale, the richer and more intense the color. And the more intense a diamond’s color saturation, the more it will be worth. For example, a Fancy Intense Yellow diamond will be worth more than a Fancy Light Yellow. Color intensity is widely considered the most important factor when it comes to determining the value of a natural colored diamond. (I'll discuss value in a bit more detail below.)

- Color Modifiers

Many colored diamonds contain secondary and even tertiary color modifiers, or overtones. In the case of a fancy yellow diamond, these are most commonly brown, green and orange. Diamonds with overtones are referred to by name incorporating all colors. For example - “greenish yellow” or “brownish greenish yellow.” The presence of brown as an overtone can have a possible negative impact on the value of a natural yellow diamond, while the presence of orange or green, given their rarity, may actually enhance the value.

Separate from overtones are split grades, or diamonds that exhibit two colors. (For example – “green-yellow”) Split grades can also affect the value of a yellow diamond, but that depends entirely on the combination of colors. For instance, a brown-yellow diamond may cost less than an intense yellow, but a green-yellow will likely cost more.

Clarity

Natural yellow diamonds are more abundant than other colors so finding one with a high clarity is not as difficult as in pinks, blues, reds, etc. Additionally, yellow diamonds in general tend to contain fewer inclusions than other colored diamonds. In fact, according to Gems and Gemology (2008), nearly 75% of all yellow diamonds attain a clarity grade of VS or higher.

Shape

Yellow diamonds can be found in any shape. Again, because they are more readily found in nature than other colors, and often in clean, richly colored rough, there are few limitations in cutting. However, fancy shapes, especially radiants and cushions are most common.

Value

Yellow is certainly one of the most common in the world of fancy color diamonds. To put it into perspective, roughly 60% of all fancy color diamonds fall somewhere in the yellow range. Because of their relative accessibility, prices are reasonably low when compared to much rarer colors such as purple or green. For this reason, yellow diamonds are quite popular and often serve as a gateway into the fancy color universe. Of course, as with any diamond color, a combination of large size, high clarity, and saturation of color will command much higher prices.

Comments and questions are always welcome!

[finessediamonds]

A Season To Celebrate

Thank you for all your support this year. We wish you a wonderful holiday season full of love and joy! Here’s to another fabulous year!

[finessediamonds]

Get To Know Us

Hello Blogosphere!

We’re excited to join the awesome world of the online written word and hope to build a community full of gemologists, jewelers, designers, collectors, and beyond. We hope to share some wisdom, exciting news, and most importantly, beautiful gems and jewels.

Our team is full of knowledge and we aim to share it. But while we certainly know a whole lot about diamonds, colored gems and jewelry design, we want to hear from you! It’s not exactly fun to talk to yourself, so we hope to hear your voices in the comments.

If you have questions, or topic ideas to share with us, please reach out!

Here’s to the start of something smart and sparkly!