Diamonds come in a variety of colors, ranging from colorless to yellow, brown, pink, orange, green, blue, violet, gray, black, and even red. However, most diamonds found in nature are actually colorless or pale yellow. The presence of color in diamonds is due to trace elements and structural defects in the crystal lattice structure during formation. Understanding what causes color in diamonds can help determine how rare and valuable colored diamonds are compared to common colorless diamonds.
What Causes Color in Diamonds?
Diamonds are made of pure crystallized carbon. When trace elements get trapped in the crystal lattice during formation, they can impact the absorption and reflection of light, causing color. Here are the main factors that produce color in natural diamonds:
Nitrogen – Nitrogen is the most common trace element in diamonds, present in nearly 98% of diamonds. If nitrogen atoms replace carbon atoms in the crystal structure, they can absorb light in the blue end of the spectrum, causing a yellow tint. The more nitrogen present, the more intense the yellow coloration.
Boron – Boron impurities in the crystal structure result in blue coloration in diamonds, by absorbing red and yellow light. The stronger the boron concentration, the bluer the diamond color. Blue diamonds contain boron levels between 5-100 parts per million.
Lattice Defects – Structural irregularities like missing carbon atoms in the crystal lattice also impact light absorption, resulting in pink, red, brown, and orange coloration depending on the type of defect. These are known as plastic deformations.
Radiation Exposure – Diamonds containing nitrogen that are exposed to natural radiation over long periods of time can turn green, blue, or black. The radiation knocks nitrogen atoms out of position, altering light absorption.
Chemical Reactions – Exposure to chemicals like hydrogen during formation can cause purple, pink, red, and orange colors in diamonds. The chemicals react with the crystal structure.
What are the Most Common Diamond Colors?
Here is a table summarizing the most frequent natural diamond colors, from most to least common:
| Diamond Color | Description |
|---|---|
| Colorless | Absolutely no color. Considered the most desirable. |
| Near Colorless | Faint yellow or brown tints. Very hard to detect. |
| Light Yellow | Noticeable but faint yellow tint. |
| Fancy Light Yellow | More visible yellow color. Called fancy colors. |
| Fancy Intense/Vivid Yellow | Rich yellow color. Rare and valuable. |
| Brown | Common, less desirable. Caused by lattice defects. |
| Pink | Rare, caused by deformities. Fancy color. |
| Blue | Boron impurities. Fancy color, very rare. |
| Green | Radiation exposure. Fancy color. |
| Red/Purple | Extremely rare fancy colors. |
As you can see, colorless, near colorless, and light yellow diamonds are the most abundantly found in nature, making up over 98% of gem-quality diamonds mined. Intensely colored yellow, pink, blue, green, red, or black diamonds are far more rare.
Grading Diamond Color
The Gemological Institute of America (GIA) developed the diamond color grading system used around the world today. It grades diamonds on a scale from D to Z, with D representing colorless and increasing presence of yellow/brown up to Z. Here is a breakdown of the GIA color scale:
| GIA Grade | Color Description |
|---|---|
| D | Absolutely colorless |
| E, F | Colorless |
| G, H, I, J | Near colorless |
| K, L, M | Faint yellow |
| N to Y | Very light to light yellow or brown |
| Z | Light yellow or brown |
Diamonds graded D-F are considered “colorless” and the most valuable. G-J are near colorless and still very high quality. Faint yellow diamonds graded K-M can offer excellent value. Beyond Z, diamonds begin to show more visible tints of yellow or brown.
The best way to judge a diamond’s true color is by comparing it to a set of master stones under controlled lighting and viewing conditions. A trained gemologist can grade color accurately using a diamond color grading system. Always get an independent diamond grading report like a GIA certificate when purchasing.
Do All Diamonds Contain Impurities?
Nearly all natural diamonds contain some amount of impurities in the form of trace elements or crystal structure irregularities. These impurities are what give diamonds their color. However, a very rare subset of diamonds called type IIa have no measurable nitrogen impurities, making them chemically pure.
These exceptionally rare diamonds comprise just 1-2% of gem diamonds mined. Type IIa diamonds can achieve the highest D-E-F color grades on the GIA scale when they have no structural defects causing color. They also can exhibit the highest clarity grades. Some famous colorless gems like the Hope Diamond are type IIa diamonds.
While the most desirable diamonds are colorless, colored diamonds exhibit a rainbow of hues from yellow to pink, blue, green and more. Their colors come from structural anomalies and/or trace impurities present during their formation deep underground billions of years ago. Understanding the geological factors that produce color leads to a deeper appreciation for these rarer colorful gems.
What Are Fancy Colored Diamonds?
Diamonds exhibiting pronounced color saturation beyond the normal Z-graded scale are classified by gemologists as “fancy color” diamonds. This includes vivid/intense yellow, pink, blue, green, red, purple, orange, and black.
Fancy colors are extremely rare – making up less than 1% of diamonds mined worldwide. However, they can command huge premiums over colorless diamonds due to their scarcity. Here are some key facts about fancy colored diamonds:
– Fancy vivid/intense colors are more prized than lighter tones. The strongest saturation commands the highest value.
– Pure spectral hues like vivid yellow, pink and blue are more prized over secondary blended hues like orange (yellow + red) or green (yellow + blue).
– Large fancy color diamonds are exponentially rarer than small ones, gaining immense value. Most weigh under 1 carat.
– Red and pink diamonds are the rarest and most expensive. The Pink Star diamond sold for $71 million!
– Natural fancy colors are much more valuable than treated diamonds. Treatment is hard to detect.
– Fancy colored diamonds are graded by GIA for hue, saturation, and tone on official reports.
– Not all natural fancy colors are desirable, like brown and some grays. Impact and beauty matter.
Fancy color diamonds provide a way to add vibrant, eye-catching hues to jewelry. Their prestige and romance fuels demand. For investment and collecting, they provide an alternative to top colorless gems.
How Rare Are Naturally Colored Diamonds?
Out of all diamonds sourced from mines globally each year, only about 0.001-0.005% exhibit natural fancy colors, making them incredibly rare. To put this in perspective:
– Only 1 in 10,000 diamonds is fancy color, or 0.01%
– About 20 tons of rough diamonds are mined yearly, producing 100 million carats of polished stones
– Just 1-5 million carats are fancy colored, mostly faint to medium tones
– Only about 50,000 carats are rated fancy vivid or intense color
– There are less than 50 pure red diamonds known to exist in the world
The highest concentrations of natural fancy diamonds come from the Argyle mine in Australia (pink, red, purples) and the Karowe mine in Botswana (blues, pinks), but these mines are being depleted. As production falls, fancy colored diamond prices continue rising.
Are Colored Diamonds Always 100% Natural?
No, not always. Some colored diamonds undergo artificial treatment or enhancement to intensify or change their color:
– HPHT high pressure/temperature treatment can make yellows more intense or turn brown to yellow, green, or blue. Undetectable.
– Irradiation exposure can turn brown diamonds green, blue-green, or black. Usually detectable under microscopy.
– Coating/painting a diamond can produce any color. Easily scratched off.
– Synthetic diamond manufacturing can produce yellows, pinks, blues, and more. Different properties under testing.
Reputable jewelers will clearly label any treated colored diamonds or simulants like synthetic diamonds. Natural fancy colors have certificates from labs like GIA and AGS attesting to “natural color” without modification. Such verification documents prove identity and boost value.
With natural fancy color diamonds so astonishingly rare, extreme due diligence is essential before purchasing. Getting an independent appraisal can help avoid treated or artificial-colored imposters.
What Makes Colored Diamonds So Valuable?
From a rarity standpoint, colored diamonds are among the most precious gems in the world. But rarity alone does not automatically translate to high value – there must also be demand. Colored diamonds possess many attributes that drive their worth and popularity:
– Extreme mineral scarcity. Occurring at 1-2 parts per billion, natural fancy colors are true anomalies.
– Beauty and striking appearance. Vibrant colors command attention, suitable for important jewelry.
– Prestige and exclusivity. Associated with luxury, status, and glamor since antiquity.
– Investment potential. Prices continue setting new records at auction year after year.
– Increasing rarity. Mines are depleting, especially Argyle, reducing future supply.
– Historic and cultural significance of famous gems like the Hope Diamond.
– Customizability for personalized jewelry. Match a loved one’s eye color for example.
– Gemological complexity. Advanced geological factors produce the colors.
– Perfectionist collecting appeal. Assembling a complete color set is the “Holy Grail.”
There are fewer than 200 red diamonds, and a small handful over 5 carats, in the entire world. Rarity of that magnitude appeals immensely to billionaires and investors seeking temporary stores of wealth. The opportunity to own something unimaginably scarcepropels prices upwards.
How Much Do Natural Colored Diamonds Cost?
Pricing for natural fancy color diamonds varies tremendously depending on the 4Cs:
– Carat Size – Larger stones are exponentially more valuable
– Clarity Grade – Loupe clean or VVS clarity preferred
– Color Grade – Vivid/Intense hues prized over lighter
– Cut Quality – Precision cutting to maximize color display
Between those factors and the particular hue itself, prices span a huge range:
– Faint yellows ~$1,500-$3,000 per carat
– Vivid yellows ~$8,000-15,000 per carat
– Pinks ~$20,000-$80,000 per carat
– Blues ~$40,000-$400,000 per carat
– Reds over $1 million per carat
Keep in mind, those are retail prices for GIA certified natural fancy color diamonds with ideal cut proportions. Wholesale prices directly from dealers are 30-50% less. The most expensive colored diamonds ever sold at auction have fetched over $1 million per carat!
Best Uses for Natural Colored Diamonds
The unique beauty of natural fancy color diamonds lends them to several ideal uses:
– Statement engagement rings. Vivid yellow or pink central stones stand out dramatically.
– Fashion jewelry designers. Haute couture houses love rare colored gems.
– Investment grade collecting. Portable assets uncorrelated with stocks/bonds.
– Museum-worthy specimens. The Hope Diamond at the Smithsonian for example.
– Luxury watches. Colored diamonds as indexes or accents on faces, bezels, and bands.
– Bridal jewelry suites. Matching fancy yellow or pink diamonds across the whole set.
– Artistic brooches, pendants, and earrings. Stunning for black tie galas and events.
– Modern or antique jewelry remakes. Replacing colorless diamonds with new fancy colors.
– Cufflinks and neckwear for men. Yellows, pinks, blues can add flair.
For those seeking totally unique and eye-catching diamond jewelry, natural fancy colors are the pinnacle. The saturation of color brings a lively, artistic element compared to common commercial whites.
Colored Diamond Origins and Sources
The geological conditions that produce the rarest natural fancy color diamonds exist in very few locations around the world:
– **Argyle Diamond Mine** – The top source of pink, red, and chameleon diamonds until closure in 2020. Located in remote Western Australia. Rough production peaked at 40 million carats per year in the 1990s.
– **Golconda Region** – Historic source of extraordinarily rare colorless Type IIa and fancy colors like blues, pinks, yellows in India. Mined from ancient volcanic pipes near Hyderabad.
– **Premier Diamond Mine** – Discovered in 1902, this mine in South Africa has produced many of the world’s largest and most famous diamonds over 100 carats.
– **Karowe Mine** – Located in Botswana, Karowe yields unusual fancy pink diamonds as well as large white gems. Owned by Lucara Diamond Corp.
– **Kollur Mine** – A famed ancient mine in the Guntur region of India that produced historic large yellow and pink diamonds.
– **Bunder Mine** – Discovered in 2019 by Rio Tinto in Madhya Pradesh, India, this source contains bluish-green and pink stones.
– **Letseng Mine** – High in the mountains of Lesotho, this mine produces large white diamonds and some vivid blue/pink colors.
– **Diavik Diamond Mine** – Located in Canada’s remote Northwest Territories, this operation unearths yellow and pink-orange fancy diamonds.
How Are Colored Diamonds Formed in Nature?
The combination of phenomenally rare geological conditions and billion-year timescales required to create natural colored diamonds includes:
– Unique parent rock formations – Kimberlite pipes from deep magma or alluvial deposits.
– Presence of trace elements like boron or nitrogen. Or crystal structure deformities.
– Intense heat up to 2200°F and pressure up to 45,000 psi crystallizing pure carbon.
– Hundreds of kilometers of vertical transport up to the earth’s surface via volcanic eruptions.
– Extended exposure over hundreds of millions of years to natural radiation inducing structural changes.
– Earth’s shifting continental plates bringing deep material closer to the surface.
– Powerful erosion exposing the diamond crystals within host rock outcroppings.
– Traditional near-surface alluvial mining or modern deep pit mining to extract the gems.
Colored diamond formation requires this exact sequence spanning billions of years. Slight changes in any geological factor alters the final result. It is astonishing that any diamonds form with vibrant colors at all given the numerous variables at play in their genesis environment.
Notable and Famous Colored Diamonds
Some of the most legendary, record-breaking colored diamonds include:
– Hope Diamond – 45.52 carats, fancy dark grayish blue. Housed at the Smithsonian Museum.
– CTF Pink Star – 59.60 carats, fancy vivid pink. Sold for record $71 million in 2017.
– Blue Moon – 12.03 carats, fancy vivid blue. Sold for record $48 million in 2015.
– Graff Vivid Yellow – 100.09 carats, fancy vivid yellow. Largest of its kind graded by GIA.
– Graff Pink – 24.78 carats, fancy intense pink. Sold for record $46 million in 2010.
– Wittelsbach-Graff – 31.06 carats, fancy deep blue. Sold for $24 million in 2008.
– De Beers Centenary – 273.85 carats, fancy vivid blue. Third largest mined. Displayed at Rijksmuseum.
– Daria-i-Noor – 185 carats, pale pinkish brown. One of the oldest diamonds, displayed in Tehran.
– Koh-i-Noor – 105.6 carats, colorless. Part of British Crown Jewels, steeped in history.
– Dresden Green – 40.70 carats, natural fancy green. First major green diamond discovered.
Conclusion
In the world of colored diamonds, color is king. While common colorless diamonds are attractive for their brilliance and fire, fancy color diamonds captivate with their rarity and rainbow hues. Finding a diamond exhibiting intense color saturation naturally is near impossible – the ultimate treasure hunt. Colored diamonds have inspired passion and awe for centuries, from ancient India’s mines to modern day auction houses. For diamond lovers and connoisse
