GIA: Gems & Gemology: Colored Diamonds Preface

While colored diamonds have been known and admired for centuries, the more widespread passion for them is a relatively recent phenomenon. In the not-so-distant past, only large, historic diamonds such as the Hope or the Dresden Green commanded much attention even within the gem and jewelry community. Today, we have come to appreciate the beautiful range of natural-color colored diamonds as well as their rarity: available in relatively small quantities, yet just plentiful enough to sustain an active market. It is an exciting time in which the consumer and the jewelry industry alike are learning that few other gemstones occur in the depths and ranges of color seen in diamonds. It may be the only gem where stones with the least color and those with the most color carry the highest premiums.

Although colored diamonds comprise only a small percentage of total mine production, they are often the center of attention at major auctions or at closely watched media events such as the Academy Awards and the Cannes Film Festival. What has caused this change?

Since the late 1970s, developments in areas such as diamond cutting, mining, marketing, and grading have helped put colored diamonds squarely in the public eye. While much of this activity has been recent, Gems & Gemology has a long history of publishing reports on colored diamonds. This volume of Gems & Gemology in Review presents a selection of the articles and notes on colored diamonds that have appeared in the journal since its inception in 1934. Before the sections of this volume are introduced, let’s take a brief look at the developments mentioned above and their impact on our perception of colored diamonds.

Cutting Innovations

Historically, colored diamonds were manufactured in the same shapes, cutting styles, and proportions as their colorless and near-colorless counterparts. That began to change in the 1970s, as a handful of diamond cutters began experimenting with ways to attain better yield from rough and create new face-up appearances. Little did they realize they were laying the foundation for a revolution in the availability of colored diamonds in the marketplace. By the mid-1970s, New York manufacturers such as Stanley Doppelt and Henry Grossbard were devising variations on Basil Watermeyer’s 1971 Barion cut, a square mixed cut whose step crown and modified-brilliant pavilion improved brilliance and increased yield over the traditional step cut. Their assumption was that the increased scintillation from the mixed cut would better disguise inclusions, resulting in a more pleasing appearance. But as both Doppelt and Grossbard eventually discovered, their experimental proportions and facet variations also strengthened the face-up color of light yellow and other yellow diamonds.

By the late 1970s and early 1980s, the trade had become aware of the full potential of these new cutting styles. Doppelt, in conjunction with diamantaire Louis Glick, introduced the StarBurst cut, which helped popularize yellows. Grossbard, meanwhile, purchased an off-color 109 ct diamond named the Cross of Asia at Sotheby’s Zurich auction in 1976. His decision to refashion this diamond into his new radiant cut resulted in a 79 ct Fancy yellow* Flawless diamond. Despite the loss of 30 carats, the renamed Radiant Cut diamond was considered significantly more valuable than the original Cross of Asia.

With the success of the StarBurst and radiant cuts, more manufacturers began recutting light yellow diamonds into these new styles to achieve face-up color grades of Fancy Light or Fancy. The new cutting styles moved away from maximizing white light return, fire, and strongly contrasting scintillation patterns—the aspects of cut that are sought after in near-colorless diamonds—to improving and intensifying color appearance. Key features of these new cutting variations were half-moon facets on the pavilion, French culets, and a greater number of facets in general. Over time, the new shapes and cutting styles were used not just during recutting but also on diamond rough, a practice that resulted in better color grades and weight retention. As a result, the manufacturing of light yellow rough became more profitable. Even more than increased mining output, this revolution in cutting was responsible for the greater availability of intensely colored yellow diamonds in the marketplace. Over time, these cutting variations were successfully applied to a variety of diamond colors. Today, most colored diamonds are manufactured in the various styles that maximize their face-up color.

Experimentation in diamond cutting continued worldwide, and many of these innovations were applied to colored diamonds. For example, Gabi Tolkowsky’s “Flower Cuts” (the Marigold, Dahlia, Zinnia, Sunflower, and Fire Rose) from the late ’80s were designed to increase yield and brilliance in shallow rough unsuitable for traditional proportions. They were also found to help lighten dark brown diamonds and intensify the color appearance in lighter ones.

The Argyle Mine and Its Marketing Efforts

The discovery of the Argyle mine in Western Australia during the late 1970s marked another turning point in the availability of colored diamonds. Within a few years of coming on line in 1982, the mine became the largest volume producer of diamonds in the world. A very high percentage of Argyle’s production was in brown diamonds, which had never received much recognition in the marketplace. As the mine’s production soared, however, Argyle set out to change that.

From the early ’90s on, Argyle aimed its advertising at the large customer bases in the United States and Japan, created an alluring image for brown diamonds by connecting them with festive and sophisticated tastes. A key aspect of this campaign was associating the diamonds’ broad range of brown colors with “champagne” and “cognac.” Jewelry design contests featuring brown Argyle diamonds raised further awareness, and high-profile designers such as Michael Bondanza and Cornelis Hollander began using them in their creations. Prior to this, such extensive marketing efforts were typically limited to diamonds in the near-colorless range. Creating such positive associations for a product long ignored was a significant innovation, and its impact continues to be felt.

Additionally, Argyle acquired a certain cachet as the only mine that consistently produced small quantities of fine pink diamonds. Previously, the production of pinks had been sporadic at best, so these diamonds immediately seized the industry’s attention. Like the browns, the Argyle pinks were marketed in innovative ways. Special annual “tenders” of the few top-quality pinks garnered considerable coverage in the trade press. Initially these auctions were held at a luxury hotel in Geneva, but in recent years they have traveled worldwide to accommodate the many potential buyers who want to view these diamonds prior to bidding on them. In addition to the pinks offered at tender, Argyle sold smaller ones directly to jewelry manufacturers and designers, who pavé set them for maximum impact. This eventually stimulated a trend toward colored diamond pavé work in general.

The Impact of Auction Sales, Exhibitions, and the Media

Yet another watershed event for colored diamonds came with the 1987 auction of the Hancock Red at Christie’s New York. This 0.95 ct purplish red diamond sold for over $926,000 per carat, still the record price per carat for any gem ever sold at auction. Virtually overnight, colored diamonds became part of every diamantaire’s conversation. Auction houses also began to offer more colored diamonds at the pinnacle of their respective colors. Diamonds in the “end grades” of Fancy Deep, Fancy Intense, or Fancy Vivid became regular highlights. While the record of the Hancock Red has yet to be topped, colored diamonds continue to command the highest per-carat prices of any gems. At two major auctions in 1995, a 7.37 ct Fancy Intense purplish pink diamond sold for $818,863 per carat and a 4.37 ct Fancy Deep blue fetched $569,000 per carat. More recently, a 0.90 ct Fancy Vivid green brought $736,111 per carat in 1999, while a 3.95 ct Fancy Deep blue sold for $420,557 per carat in 2001. These steep prices continued to hold their ground up to the time of this writing. A 3.10 ct Fancy Vivid purplish pink diamond sold for $592,129 per carat in June 2005; four months later, a 4.24 ct Fancy Vivid blue brought $426,415 per carat.

Even with the occasional exhibition of colored diamonds from royal and state collections, historically there were few opportunities for the public to see significant numbers of colored diamonds in a wide range of colors. Fortunately, over the course of the last century, a handful of passionate individuals have managed to bring them to the attention of broader audiences. Atanik Eknayan exhibited his collection of colored diamonds at the St. Louis Exposition in 1904, where it was said that more than 70 different colors were on display. Long-term loans to museums also provided opportunities for viewing colored diamonds, such as Andre Gumuchian’s 40-plus-diamond Spectrum Collection, which was on view at the American Museum of Natural History in New York from 1976 to 1986. Between 1981 and 1984, Eddie Elzas’ Rainbow Collection of approximately 300 diamonds toured a number of venues, including the American Museum of Natural History and the Los Angeles County Museum of Natural History. Alan Bronstein and Harry Rodman’s Aurora Collection, which now consists of 296 colored diamonds, was exhibited at the American Museum of Natural History from 1989 to 2005. Their Butterfly of Peace Collection, developed over a 12-year period, was on display at the Houston Museum of Science from 1994 to 1996 and the Smithsonian Institution from November 2004 to July 2005.

Other temporary museum exhibitions have brought colored diamonds to a much larger audience. Notable examples were “The Nature of Diamonds,” which premiered in New York and traveled to San Diego in 1999, and “Diamants,” which opened in Paris in 2001. Blue diamonds were chosen by De Beers to express the feeling of uniqueness in witnessing the start of a new millennium in 2000. Centered on the 27 ct Fancy Vivid blue Heart of Eternity, a group of 11 blue diamonds were featured as part of the De Beers Millennium Collection. This collection was unveiled at the Millennium Dome in London on New Year’s Eve 2000. Together with the 203 ct D-color, Flawless De Beers Millennium Star, these blue diamonds sent a strong message to the public about diamonds and their timeless beauty.

The Smithsonian’s summer 2003 “Splendor of Diamonds” exhibit reportedly received between 10,000 and 15,000 visitors a day. In addition to the impressive attendance figures, the seven diamonds that made up the “Splendor” exhibit drew much press and television coverage and were regularly discussed as embodying the idea of rarity. Two years later, the Natural History Museum in London premiered “Diamonds” in the summer of 2005. The exhibit highlighted a group of unique diamonds (including some from the “Splendor” exhibit) and featured historic and modern jewelry as well as mining displays.

With this increased exposure has come trade backing for colored diamonds in ways that had not existed before. In 2003, the Natural Color Diamond Association (NCDIA) was established. To date, the association has sponsored fashion shows in conjunction with trade and media events, and has launched a website to help consumers and diamond professionals alike better understand colored diamonds.

Of particular importance to the growth in consumer awareness of colored diamonds is the greater coverage by the mainstream media of colored diamond purchases and adornment by celebrities. For example, in 2002 and 2003 considerable attention surrounded the 6 ct pink diamond in the engagement ring given to singer/actress Jennifer Lopez by her then-fiancé, actor Ben Affleck. Other large colored diamonds have adorned celebrities at media events, such as Halle Berry wearing the 5.54 ct Pumpkin diamond (part of the “Splendor of Diamonds” exhibit) when she accepted her Best Actress Oscar in 2002. She followed this at the 2003 Golden Globe awards by wearing a blue diamond pendant and ring. While the presence of colored diamonds at such events isn’t a new phenomenon, the attention that now surrounds these gems is unprecedented.

Refinements in Grading and Changes at the Laboratory

During the late 1980s, GIA began work on strengthening its system for color grading colored diamonds. While the basic framework of the system had been in place since the mid-1950s, GIA laboratory officials recognized that it needed to be refined to respond to the greater availability of natural-color diamonds in a broader range of colors. Building on the format of the Institute’s Colored Stone Grading System, which had been introduced into its education courses in 1980, this research effort continued through the early 1990s. A preliminary summary was presented at GIA’s 2nd International Gemological Symposium in Los Angeles in 1991 (King, 1992). In early 1995, GIA formally introduced the modifications, which included the use of two additional Fancy-grade terms, Fancy Deep and Fancy Vivid. Today, the GIA color grading system is used globally as a consistent way to communicate color in colored diamonds.

Since these modifications were introduced, demand for GIA’s colored diamond grading services has steadily increased. Between 1998 and 2003, for example, requests rose 68% overall. It is important to bear in mind that greater demand for grading services is better seen as an indicator of colored diamonds’ popularity rather than increased mining supply. Colored diamonds that might not have received reports in the past are now routinely submitted. Yet of the hundreds of thousands of diamonds submitted annually to GIA for reports, less than 8% are colored diamonds and most of those are yellow.

Another trend we are seeing is a shift in the type of grading report requested. Of the two types of reports GIA offers for colored diamonds—a comprehensive grading report, and what is known in the trade as a “color only” report—in recent years we have seen a greater proportion of requests for the comprehensive report. For example, in 1998, 57% of the requests were for the comprehensive report, whereas this number had grown to 75% in 2003. As the value and awareness of colored diamonds have increased, interest in the more comprehensive report has grown as well.

While they are not the focus of this book, diamond treatments have become much more prevalent since the ’90s. The last few years have also seen synthetic colored diamonds become commercially available for the first time. Indeed, their importance to the gem industry prompted the first volume in the Gems & Gemology in Review series, Synthetic Diamonds (2005). Treated-color diamonds and colored synthetic diamonds can provide a benefit for some consumers because they offer affordable alternatives for those interested in the unusual, and in some cases they encourage future purchases of natural stones. However, they can also present serious identification challenges. An understanding of the properties of natural-color colored diamonds, especially the causes of the many hues in which they occur, is critical to meeting these identification challenges. Many of the articles and notes reproduced here have added significantly to our knowledge of the physical and optical properties of natural-color diamonds—and, thus, to the ability of the research gemologist to separate them from their synthetic and treated-color counterparts.

Notes Regarding the Organization of the Book and the Color Terminology Used

Most of the information in the present volume was originally published in Gems & Gemology between the years 1935 and 2006. The entries appeared as feature articles, shorter “Notes & New Techniques,” reports from the GIA Laboratory (originally “Developments and Highlights at GIA’s Labs,” but known as “Lab Notes” since 1981), or “Gem News” (now “Gem News International”) items. Also included are summaries of relevant presentations at GIA’s International Gemological Symposia in 1991 and 1999, which originally appeared in Proceedings volumes published by the Gems & Gemology staff.

This information is organized in four parts:

1. Historic and Notable Colored Diamonds

2. Characterization of Colored Diamonds

3. Color Grading of Colored Diamonds

4. Colored Diamonds with Unusual Characteristics

Each of the book’s four parts is preceded by an introductory essay. Within each part, the material appears in largely chronological order to help the reader follow the evolving areas of interest and understanding in studying these gems. In many cases, the original entries have been reformatted to fit the style of this volume. Note, too, that the earlier angstrom (Å) units have been converted to nanometers (nm), the internationally recognized SI unit (1 Å = 0.1 nm). Following the Epilogue, which looks at the future for colored diamonds, information on each contributor is consolidated in the About the Authors section. Starting on page 298, the reader will find a consolidated bibliography containing all the references cited in the original publications. This method was chosen to avoid repetition, since many of the references appear in several entries.

It is important to remember that color descriptions on laboratory reports have changed over time, especially since GIA introduced its modified system in 1995. Because of these differences, it can be challenging to compare some past color descriptions that are no longer used with GIA’s newer Fancy grades. Where appropriate, a note of clarification will accompany the entry.

This volume also contains the works of non-GIA authors who used terms similar to those associated with GIA’s colored diamond color grading system. The use of GIA terms by non-GIA authors does not imply that the grading, and thus the description, is the same as would be applied by GIA. While GIA does not discourage others from using the terminology it has developed, the Institute has no way of verifying the color standards, methodology, equipment, or training used by other laboratories.

Finally, a booklet of color reference charts is included with this volume to help the reader understand the relationship of color appearances as they are described in GIA’s color grading system for colored diamonds. While the charts do not attempt to represent all of the colors in which diamond occurs, they do reproduce examples from a wide range of colors encountered in the jewelry industry. Earlier versions of some of these charts were first published in conjunction with articles in this book – such as the grading and characterization articles on blue, pink, and yellow diamonds – while others were developed specifically for this booklet. This booklet will help the reader gain a better understanding of these intriguing diamonds and their varied color appearances. Please note that, due to the inherent difficulties of controlling color in printing (as well as the instability of inks over time), the color of images in these charts may differ from the actual color of the diamonds they are intended to represent.

John M. King
Editor

*Graded prior to the GIA Laboratory’s modifications to its colored diamond color grading system.

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