Statement of William E. Boyajian, President,
Gemological Institute of America,
and on behalf of the Word Diamond Council
Testimony Before the Subcommittee on Trade
of the House Committee on Ways and Means
Hearing on Trade in African Diamonds
September 13, 2000
Mr. Chairman and members of the subcommittee, I am William E. Boyajian, President of the Gemological Institute of America (GIA). Founded in 1931, GIA is the largest educational and research institution in the world, with some 700 employees on campuses in eight countries on three continents. Incorporated as a 501(c) 3 public benefit corporation, GIA’s mission is to educate and serve the gem and jewelry industry, creating standards of professionalism to benefit the trade and, therefore, uphold the public trust in diamonds and other gemstones. We educate some 15,000 people each year in gemological training programs and conduct state-of-the-art gemological research to ensure the integrity of gems. Our Gem Trade Laboratory grades most of the major polished diamonds that are bought and sold around the world each year, estimated at a value of some $3 billion at the wholesale level. We also design and manufacture fine gemological testing equipment to assist jewelers in identifying and grading diamonds and other gemstones.
Over the past 18 months, interest has been expressed by certain governmental and non-governmental organizations in establishing a mechanism to determine the “country of origin” of gem diamonds. These organizations suggest that if such a determination could be made, the diamonds being mined in particular conflict countries could be identified and banned from international commerce. This action would deprive the combatants involved of an important source of revenue for their activities.
Of the hundred-plus millions of carats of diamonds produced annually, only a few percent originate in conflict countries. Despite this fact, public pressure is being placed on the jewelry trade to quickly develop a mechanism to segregate those diamonds that are illicit. GIA has therefore been asked to research, review and comment on the feasibility of identification of country of origin of rough and polished gem diamonds. This report sets forth the position of GIA as to whether the country of origin for gem diamonds can be determined.
There are two different parts to the problem of determining the country of origin – identifying the geographic source of rough or polished diamonds, and tracking diamonds from their source through the diamond “pipeline.” Can an analytical means be developed to determine the geographic source of rough and polished diamonds whose origins are uncertain? Can a procedure be organized for tracking particular diamonds from the mine through manufacturing and retailing to the consumer, to prevent diamonds originating in certain countries from being sold? This report will address these questions.
Based upon current knowledge, no practical means exist today for determining the country of origin of rough or polished diamonds, although means may be developed to make such a determination for some percentage of rough diamonds. We believe that steps can be taken to track diamonds from the mine through to the manufacturer and retailer. To succeed, such a tracking system would require increased cooperation among all organizations of the diamond industry.
This report will focus on discussing the technical considerations involved in determining the country of origin for rough and polished diamonds, and will conclude with a few remarks about a diamond tracking system. Before discussing these issues, it is first necessary to make a few preliminary comments as background information.
General Comments Relevant to Determining Country of Origin
Diamond Formation. Diamonds crystallize deep in the earth’s mantle, and are brought to the surface through magmatic activity. At the surface, the diamonds occur in certain kinds of volcanic rocks (kimberlites and lamproites). From the primary deposits in these rocks, some diamonds are released during rock weathering and can become concentrated in secondary alluvial deposits formed along rivers, or in the marine deposits under the ocean along the western coast of southern Africa.
Like other minerals and rocks, diamond crystals contain within themselves a record of their geologic history in terms of their morphology, detailed chemical composition, growth and etching features, and inclusions. Interpreting this record is a current focus of geological research to better understand the physical conditions and processes that take place where diamonds crystallize in the mantle. For scientists, diamonds are particularly valued for this purpose because they, and their mineral inclusions, undergo so little alteration after the diamonds are emplaced in the crust. Thus, this record provides much information on the conditions of growth of diamonds, and some information on their post-growth conditions, in the mantle. However, the record provides little or no information on the geographic source of diamonds in the earth’s crust where they are found and mined. Thus, the features of diamonds may provide no indication of their country of origin.
Meaning of “country of origin.” In discussions on the subject of determining geographic source, it should be understood that country of origin means the country where the diamonds are mined or extracted, and not necessarily the places where they were deposited in the earth’s crust. Diamonds originally emplaced in several primary deposits (in one or more countries) could be weathered out of their original host rock, be transported by rivers, and become concentrated in a secondary deposit in another country. If identifying characteristics existed for the diamonds from a particular primary deposit, these features may or may not be retained during the weathering and transport of the diamonds to secondary deposits. Moreover, from a single secondary deposit in a conflict country, one could potentially find diamonds with characteristics distinctive of several primary deposits in one or more other countries. Therefore, these characteristics would provide no information on where the diamonds were mined (i.e., in a conflict country), but only where they were deposited, possibly in a neighboring non-conflict country that depends on diamond exports to maintain economic and social stability.
Distance from the source. As diamonds travel further from their geographic source through the diamond “pipeline,” the likelihood of recognizing their source decreases. In most cases today, a manufacturer purchases an assortment of rough diamonds, possibly from a number of different geographic sources that are not all fully known to them, to polish as gemstones. The contents of this assortment are often determined based upon the particular needs and capabilities of the manufacturer. Mixing diamonds from several sources also provides for a more equitable distribution of diamonds among manufacturers. These factors all contribute to an uncertainty about geographic source as the diamonds are bought and sold in the trade.
Loss of features during manufacturing. Even if a high proportion of rough diamonds from a geographic area does have some distinctive physical characteristics, many such characteristics are lost during the manufacturing process to produce polished gemstones. This means that even fewer characteristics exist for determining the geographic source of polished diamonds.
Acceptable proof of a country of origin. Among the organizations advocating that the jewelry trade takes steps to identify diamonds from conflict countries, there has yet to be much discussion on what would be considered acceptable proof that the features of particular diamonds establish that they do or do not come from a conflict country.
Unique Characteristics of a Diamond
Determination of the country of origin depends upon the existence of characteristics that are unique to diamonds from a particular geographic source. Possible distinctive characteristics include visual features of the rough or polished diamonds, gemological properties, spectrum bands, and chemical composition data. To the extent that the diamond crystals in a deposit have a common geologic history, they may have such similar characteristics that are unique to that deposit. Documenting these characteristics may then allow the determination of a country of origin. Such unique characteristics would need to be established on the basis of statistical studies of numerous diamonds from an area, with the resulting information being compiled into a database. Many diamonds from all similar sources would have to be investigated to check claims of uniqueness.
Characteristics of diamonds that are potentially diagnostic of geographic source fall into several categories:
1) Visual features of rough diamonds – size, crystal morphology, surface features (resulting from growth, etching, abrasion, and radiation exposure), color, and inclusions.
2) Visual features of polished diamonds – size, color, clarity, transparency, fluorescence, inclusions, and quality of polish.
3) Physical properties – visible, infrared, luminescence, and Raman spectra, anomalous birefringence patterns, and measurements of other physical property.
4) Detailed chemical composition analysis – trace elements, trace element ratios, and isotopic data.
Determining unique characteristics. Geologic studies have shown that in some primary deposits, all the diamond crystals have a common geologic history. In other deposits, the diamonds have differing histories (that is, they originated from different areas in the mantle). Secondary alluvial deposits contain diamond crystals from all primary deposits sampled by the waters that transported the crystals to the alluvial deposit; in some cases, this transport can extend over great distances. At present, there exist scattered scientific studies of diamonds from several deposits, limited mining records, and anecdotal evidence which suggest that, on average, diamond crystals from some deposits do have some identifying characteristics (such as shape, surface features, and color). However, the existing data are too limited and too sketchy to identify the place of origin of any given random diamond crystal with a high degree of certainty.
In order to determine if certain characteristics are typical of diamonds from a geographic source, one would need to gather many kinds of analytical data. These data would be required from a sufficient number of diamonds known to be from a particular area, to find both the average characteristics and the unusual ones, in order to have a statistical degree of confidence in this information.
To further determine whether these average characteristics are diagnostic of diamonds from a particular deposit, one would need the same large quantity of data, from a similarly large number of diamonds, from each of the other commercial diamond-producing areas around the world. Collection of these data could be more easily accomplished for primary deposits that occur in well-defined areas, and under the control of major mining companies. Collection of data on diamonds from secondary alluvial deposits would be much more difficult to achieve both because there is less control over mining activities (undertaken by numerous groups or individuals on a legal or illegal basis), and because the productive areas may be geographically very large. For both primary and secondary deposits, a determination would need to be made about what would constitute a truly representative sample of diamonds from an area. Statistical studies would then need to be carried out to analyze the characteristics of the diamonds from each deposit, to determine if such characteristics are unique to the diamonds from that deposit.
Results of these statistical studies would need to be compiled into a database, against which the features of diamonds of unknown source could be compared. At this time, such a database does not exist. Gathering sets of diamonds from known deposits would be a first step toward building this database. An appropriate procedure to document the characteristics of these sets of diamonds would need to be agreed upon and implemented. Creation of this kind of information database is a large research undertaking, and would likely take a several years (and millions of dollars) to complete. Even then, one cannot rule out the possibility that diamonds from some deposits will not have features diagnostic of their geographic source, and that some atypical diamonds will exhibit characteristics suggestive of deposits other than the one from which they were mined.
Source determination for rough versus polished diamonds. Various features have been suggested as being potentially characteristic of rough diamonds from a particular country. These include crystal morphology, surface features, inclusions and internal structure, shape or surface profiling, and trace element chemistry. While diamonds from some deposits seem to have similar characteristics, no studies have been published which indicate that mixed parcels from multiple sources could be separated on the basis of such characteristics. Many of the surface and shape features present on rough diamonds are lost during the manufacturing process, leaving even fewer characteristics of polished diamonds that are related to their geographic source.
Over the past 50 years, millions of polished diamonds have been examined, and their gemological properties carefully documented, in gemological laboratories during the production of quality grading reports. During this extensive opportunity to examine numerous polished diamonds, no observations have been reported which indicate that polished diamonds from a particular geographic source could be recognized during the grading procedure. Distinctive light reflection patterns arising from the arrangement of facets, and the use of logos or other identifying marks, have each been proposed for distinguishing polished diamonds. Except for a few isolated studies, no extensive research work has been undertaken to establish if any of these features will allow the recognition of particular polished diamonds originating from conflict countries. On the contrary, past observations suggest that the features of polished diamonds are not distinctive of geographic origin.
Documentation of spectra or other physical properties. Features of the spectra of diamonds, or measurements of other physical properties, vary greatly within the diamonds from the deposits that have been studied. Such features result from the conditions of growth or post-growth to which the diamonds were subjected to in the mantle. While some generalizations can be made (for example, many diamonds from the Premier mine in South Africa display strong blue ultraviolet fluorescence), no data have been published which propose that spectral features or other physical properties are unique to diamonds from a deposit, or to claim that all diamonds from a deposit exhibit given features.
Documentation of chemical composition. Compared to most other minerals, diamond is chemically quite pure. Nitrogen may occur at concentrations up to 0.5%. Other trace elements can occur at very low concentrations (levels of parts per million or parts per billion).
Detection of trace elements at these very low levels in diamonds requires sophisticated and sensitive analytical techniques, such as neutron activation analysis or laser ablation mass spectrometry. Such techniques are expensive and time-consuming, taking hours per sample to complete an analysis. The former technique requires the diamond to be irradiated in a nuclear reactor, and then the radioactive decay of each of the various trace elements present in the diamond to be counted using gamma spectroscopy methods. The latter technique, also referred to as LA-ICPMS, is a destructive method of chemical analysis, although on a small scale. A few cubic micrometers of the diamond are vaporized by a laser beam (and a tiny hole is produced), and the resulting components in the vapor are then analyzed with a plasma mass spectrometer. The small area chosen for analysis would need to be representative of the chemistry of the entire diamond. Achieving a representative area may be quite difficult, because past studies have shown that diamonds can be chemically quite inhomogeneous in terms of their trace elements. This could require multiple analyzes be made of an individual diamond. A third method might be to chemically analyze the isotopes of carbon or the trace elements in a diamond, which would also be destructive to the sample. Although quite sensitive, all three techniques are impractical in terms of cost and time for analyzing a large number of diamonds. For each of these methods, the analyzed areas would need to be cleaned of surface contaminants, whose presence could prevent or render inaccurate the detection of trace elements at very low concentration levels. Data obtained from these analytical techniques would need to be compiled in a computer database, and analyzed by statistical methods.
Even if trace element data existed for diamonds from all major deposits, little or no results have been published to suggest that polished diamonds from a particular geographic source could be recognized on the basis of such information. Like mineral inclusions, the trace element composition of diamonds reflects their environment of crystallization in the mantle, and so it may vary among the crystals within a given deposit, especially an alluvial one.
Country of Origin of Colored Stones
Analogous to studying the country of origin of diamonds is that of the country of origin of various colored stones: ruby, sapphire and emerald, in particular. Several respectable laboratories have sought to compile databases on the country of origin of these stones to meet market interests by producing gemological reports on the origin of country of such gemstones.
Even with decades of independent research and the collection and analysis of comprehensive data, country of origin of colored stones is not an exact science and can more reasonably be characterized as professional opinions based on the best evidence available to date and to that lab. Such interpretations or conclusions can and do vary from laboratory to laboratory. Because of this and for other reasons, laboratories offering origin reports often state that it is their “opinion” of origin or that a stone has characteristics similar to that of certain countries.
As you can probably surmise, country of origin determinations are a hotly debated subject in the colored stone world. Because GIA has long felt that the best research data and expertise has not resulted in a standard of consistency and scientific backing acceptable to our institution, we have never entered the arena of providing origin reports on colored gemstones, and continue to hold this fundamental view. Likewise, except and until the advent of so-called conflict diamonds, GIA has never seriously been asked or even contemplated the prospects of attempting to determine country of origin in diamonds.
Conclusion
Based upon current knowledge, we do not know of any scientific way to determine the country of origin of rough or polished gem diamonds, nor do we foresee practical ways being developed in the near future. Determination of geographic source might be made for some percentage of rough diamonds, because of the additional identifying characteristics they may exhibit. However, considerable research work would be needed before one could estimate how large that percentage might be. Even in the best-case scenario, it is to be expected that a significant number of rough diamonds would not show sufficient distinctive characteristics for their country of origin to be determined.
Therefore, a chain of warranties or a system of certification to track diamonds from their country of origin through the manufacturing process to the retailer and the consumer would provide a better alternative at this time to the goal of preventing the sale of illicit diamonds. Useful discussions have already begun within the trade on how such a tracking system could operate. Some of the organizational structure for cooperation among trade groups to implement a tracking system for legitimate diamonds already exists. Such a system could be initiated rather quickly if it should become a legal requirement. This will oblige dealers to declare the true origin of their diamonds, and will in turn act as a guarantee that parcels of diamonds sold under such a system would not contain so-called conflict diamonds. Initiation of a tracking system would be an important step toward preventing illicit diamonds from passing along the diamond “pipeline” to the consumer, and the funds from the sale of these illicit diamonds being used by conflict combatants.
As a nonprofit public benefit institution, GIA remains committed to assisting the trade, governments and nongovernmental organizations in whatever way possible, to curtail the mining and flow of so-called conflict diamonds.