Ian Dun‘s Key Points • The GAA has expanded training options in recognition of the need for informed understanding of the innate qualities of diamonds. • The rise of lab-created diamonds has prompted the GAA to continually develop and deliver educational opportunities. • Accepted and precise terminology protects and informs consumers, and facilitates transparent, rational interactions and transactions. |
As the country’s premier educator in the field of gemmology, the Gemmological Association of Australia (GAA) and its members have witnessed more change in the 80 years of operation than most participants in
the local jewellery industry.
From its inception, the concept of objectively understanding and identifying gemstone materials using accessible instruments and techniques is as relevant now as when the Association was first established.
The skills of the trained gemmologist are more essential than ever, and we continue to develop and deliver the fundamental competencies and knowledge that add credibility and confidence to the decisions made by valuers, jewellers, traders and purchasers.
The steady flow of new gemstone materials into the jewellery trade from both natural and man-made sources has consistently been directed at broadening supply options for potential purchasers of high-value, high-status gemstones, in greater quantity and at lower prices.
Colour gemstones have been regularly synthesised and imitated by cheaper alternatives. Until recently, diamonds have been immune. Most imitants are structurally and chemically distinct and can be easily identified, such as cubic zirconia and moissanite.
As is well known and widely reported, this is no longer the case. We are observing exponential growth in the supply of synthesised diamonds, manufactured en masse and promoted to purchasers as ‘Lab-Grown’ Diamonds.
Fortunately, the GAA has no say in the economics of supply and demand. Our position allows our training and learning resources to concentrate on the core issues: that of identity, interventions, treatments, nomenclature and disclosure.
What has changed at the GAA?
As a registered educational charity, with negligible external funding sources, we consciously focus our attention on delivering affordable training to the community that is focused on accessibility, accuracy and understanding.
In the period since the first and second editions of the Great Diamond Debate, we have expanded our training options in recognition of the need for informed understanding of the innate qualities of diamonds, both natural and synthetic.
A specialised course called the Laboratory Grown or Natural Diamond short course was developed for the GAA by Bill Sechos in New South Wales in 2022. This new course teaches a full range of identification techniques using both handheld and specialised instrumentation.
With both theoretical and practical concepts taught in this course, small class groups use microscopy, polarised light, ultraviolet light, other forms of specialised illumination, and advanced instrumentation to analyse and identify a broad range of samples collected by the GAA for training purposes.
Recognising the desire for prompt attainment of basic levels of practical understanding, we have restructured our traditional Diamond Technology course and made tailored mini-course options available for industry training.
The micro-credentials that this program delivers are focused on efficiently demonstrating to staff the basic levels of understanding in gemstone handling, diamonds, colour gemstones, pearls and aspects of manufacturing, with plenty of opportunity for discussion and more detailed insights.
The goal here is to ensure that staff from outside the jewellery community are given quality information as early as possible.
The GAA Diploma of Diamond Technology, which was historically run as a single-year intensive part-time course, has been modularised to enable practical sessions to be delivered more frequently and across more teaching centres.
Practical Diamond Grading and Advanced Practical Diamond Grading are now delivered in all states on a regular basis, and completion of these satisfies the practical requirements of the Diploma of Diamond Technology course.
The theoretical component is delivered on a less regular basis as the intensive focus required to participate in lectures and complete coursework limits the number of potential candidates at any given time.
The Board of Studies and Examinations is overseeing a revision of the theoretical components to include an updated curriculum that is more accessible and able to be zwwdelivered by a range of specialist presenters.
It is anticipated that the revised Curriculum will be ready for delivery in the near future. With both theoretical and practical concepts taught in this course, small class groups use microscopy, polarised light, ultraviolet light, other forms of specialised illumination, and advanced instrumentation to analyse and identify a broad range of samples collected by the GAA for training purposes.
This specimen collection and newly developed testing instruments are continually reviewed and supplemented as the need arises and resources are made available.
Donations and support from within the jewellery trade have greatly facilitated the identification of new specimens and their incorporation into the teaching collections.
What’s happening behind the scenes?
In conjunction with the Jewellers Association of Australia (JAA), the GAA maintains a consistent presence at the World Jewellery Confederation (CIBJO) and adheres to the accepted gemstone nomenclature as laid out in the various Blue Books.
Consistency of terminology and accuracy of description underpins the training that the GAA offers alongside identification.
The purpose of accepted, clear terminology is to protect and inform consumers and facilitate transparent, rational interactions and transactions. While not a certifying body per se, the GAA regularly reviews certificates of many types for accuracy and is occasionally called upon to adjudicate or clarify misunderstandings.
Alongside the traditional descriptions well known as the 4Cs, the GAA also teaches the terminology and characteristic features of growth types, crystal morphology, inclusions and treatments, applicable to diamonds of natural and synthetic origin.
Observations, both visual and with the assistance of instruments, are the foundation of the
practical coursework.
Growth types, the physical structure, and chemical composition are essential elements of a nuanced identification process. It’s no longer satisfactory to simply identify diamond as a material. Its origin must be determined to establish whether it was naturally-occurring or synthetically produced.
The understanding of diamond categorisation into Type Ia, Ib, IIa, and IIb according to the presence of nitrogen in the crystal structure and how it incorporates into the lattice formation is used extensively in determining the origin of a diamond, as well as the crystal growth forms, as implied by either external or internal growth features.
Crystal structure and morphology, the presence of growth features such as twinning, hardness variations, and the presence and location of cleavage planes all inform the level of understanding of a gemmologist.
The range of classic crystallisation forms of diamonds varies according to the growth environment.
The less controlled natural environment produces predominantly octahedrally formed crystals.
High Pressure High Temperature (HPHT) diamonds grow with the cubo-octahedral faces dominant, while Chemical Vapour Deposition (CVD) diamonds grow vertically from the seed plate, and the growth patterns reflect this. Deep-UV imaging is used to help observe these characteristics.
Inclusions and their association with natural or industrial processes are essential contributors
to a complete understanding of a diamond.
Whether grading for clarity by loupe or analysing in greater detail using microscopy, inclusion analysis is a fundamental activity.
When studying by loupe, it’s very important to be aware that many inclusions can look very similar to others. Therefore, we teach and demonstrate that hand lens analysis is best undertaken in conjunction with other tests. The simple presence of magnetism or a girdle inscription can also be useful.
Trigons and external etch marks, twinning wisps, and varied crystalline inclusions in natural diamonds need to be distinguished from metallic flux and graphitised inclusions in HPHT and CVD synthetic diamonds, respectively.
Treatments and their resultant effects are identified by a range of techniques.
Alongside the emerging treatments such as radiation and High Pressure Heat Treatment, previously prevalent modifications to diamonds, such as drilling by laser, fracture bleaching, fracture filling, cutting and polishing techniques, are among those identified by instrumental techniques.
This ranges in complexity, from comprehensive microscopic analysis to reactions to illumination, covering the full range from the ultraviolet to near infrared ends of the spectrum.
The need for advanced laboratory testing to identify colour alteration of natural type IIa brown diamonds is another situation that students are taught to recognise.
Where is the GAA headed in the future?
Looking forward, it seems inevitable that synthetic and naturally occurring diamonds of all grades, in old, new and emerging cutting styles, small and large, will become increasingly intermingled and presented for assessment, as loose stones or set in jewellery.
These gemstones, with their provenance and certification lost by dissassociation, time, and incomplete narratives, will still represent value and importance to the owner, trader, or wearer.
The need for the GAA to continually develop and deliver educational opportunities for the conscientious handler of diamonds will remain.
Evolutions in testing equipment, variations and/or improvements in quality due to manufacturing and mining advances, and the development of new techniques and treatments are inevitable.
The contribution of informed individuals who can independently describe gemstone materials accurately is essential to maintaining trust and fairness.
The presence and importance of diamonds of all types are unlikely to diminish. This is courtesy of their enduring historical relevance and negligible potential for natural attrition.
Continuing our legacy, the GAA remains committed to delivering and developing relevant training for all aspects of gemmological knowledge.
The desire for knowledge and the proliferation of opinions and information from seemingly infinite sources ensure that the capacity to use validated judgement, supported by primary observations, expert use of instruments, and the ability to consider, interpret, and collaborate will be valued by students.
Indeed, satisfying these needs will remain the focus of the GAA’s education for many years to come.
THE GREAT DIAMOND DEBATE III
Table of Contents
The Great Diamond Debate Collection