Lectures from leading Gemmologists, Dealers, and Diamond Experts on a broad range of subjects but crucial topics that are most worrisome to Jewellers, Gem Dealers and Appraisers.
Branko Deljanin (CGL Canadian Gemlab, Canada)
Comparative analysis of detection portable instruments for screening and ID of Lab-Grown Diamonds
Considering occurrences of “salted” parcels of undisclosed synthetic diamonds and melee diamonds set in jewellery alongside natural diamonds, vigilance, and an understanding of standard and advanced gemmological tools are critical to ensure confidence in the supply line. While well-equipped labs can identify such non-natural character and issue a report accordingly, diamond dealers, gemmologists, appraisers and retailers need instruments that help them at least, to screen natural and some cases identify lab-grown diamonds. There are an increasing number of detection instruments and machine on the market in last 5 years that use different methods for screening/detection, e.g.:
- transparency to SW UV light,
- characteristic fluorescent/phosphorescent reaction to LWUV and SWUV light
- VIS, PL, Raman, FTIR and fluorescence spectroscopy
- fluorescence imaging
- other undisclosed techniques
Each member of the trade has specific needs on type of item to be tested (loose or mounted, size and colours), number of items needed to be tested per hour and accepted tolerance on accuracy, as well as the budget. It is advised that a potential buyer spend at least 1 day at a trade workshop on the use of standard and advanced portable instruments with samples of lab-grown diamonds before making a decision on the type of products to buy.
Elena Deljanin (Gemmological Research Industries Inc., Canada)
Morphology of diamonds as a window to origin
Morphology is a Greek word meaning a “study of form”. Morphological characteristics of diamond could only be referred to rough diamonds. Morphology of diamonds is very sensitive to change of the time – pressure component, geological environment, and growing conditions. The morphology of diamonds and their surface characteristics are very crucial for grading of diamonds. Their surface characteristics could give a picture of the geological conditions of their formation and deposition. After the Second World War, Russia became a pioneer in using rough diamonds as indicator minerals for diamond prospecting. The study of diamond morphology and diamond surface characteristics were used as tools for determining the age, conditions of formation, identification of primary or secondary deposits and many more different aspects, including estimation of cut size, clarity and color. The study of morphology could also be used as a form of diamond fingerprinting.
Ioannis Alexandris (Gemolithos Group,Germany)
How important is Antique Jewelry in 21st Century?
Buying a piece of antique jewellery is like buying a piece of history. Like a prized piece of art, the value of antique jewellery appreciates, helped by the rising interest from millennials and gen Z customers. There is much confusion when it comes to dating and valuing antique jewelry and numerous resources are needed from instruments, publications and the identity of gemstones and their cut. Premium prices can also be expected depending on the designer, manufacturer and provenance of a piece.
Jeffery Bergman (EightDimension Gems, Thailand)
Spinel history, origins, treatments, marketing & pricing
Since many famous rubies in crown jewels around the world are actually spinels, spinel is known as the great imposter of gemstone history. Fine spinels are much more rare than the rubies they often imitate, and in addition to Burma, spinel is mined in Sri Lanka, Madagascar, Nigeria, Tanzania, Tadjikstan and Vietnam. Traditional heat treating of spinels is quite rare due to the generally poor results, but surface diffusion of cobalt produces stunning vivid blues growing in popularity. Demand from jewelry manufacturers and savvy collectors has seen prices increase more than ten-fold over the past few decades with top large flawless reds and cobalt blues fetching wholesale prices of over $50,000 per carat.
John Chapman (Gemetrix Pty, Australia)
New compact instruments for origin ID of diamonds
Fluorescence of diamonds have provided a quick and easy first assessment of origin ID, like ‘PL/Jewellery Inspector’ products. Sometimes such analysis is insufficient and other techniques are needed. Crossed polarising filters (CPF) are commonly used to view, with the help of a microscope, the strain (birefringence) patterns that often can be distinctive for natural, HPHT- and CVD-grown diamonds. Combining the filters with a magnifying lens and a smartphone camera provides a very portable device to view and record the patterns in a CPF device (‘StrainView’).
Spectroscopic systems based on either PL or UV-vis-IR absorption provide a high level of ID analysis, however these systems are normally expensive and not particularly portable. By combining a spectrometer sensor to an optical system that includes both a UV laser and white light source, a compact and lower cost system can be provided, such as the spectrometer ‘InSpectrum’. These can reveal defects associated with growth and treatments.
Dr Lore Kiefert, (Gemmological Consultancy Company, Germany)
ID of Major Gems & Origin determination
Origin and treatment determination has only become an issue in the 1980s. Before then, there were very few gemological laboratories, and their task was mostly diamond grading and gem identification. Since the 1980s, three rapid developments took place nearly in parallel: More gem deposits were found, new treatments were developed, and more and more gem labs opened. With this global trend, confusion arose among the trade and privates alike, and it was necessary to go a step further and develop methods to distinguish these new origins from the traditional ones, as well as determine any treatments. The lecture will concentrate on these developments, showing opportunities as well as limitations of origin and treatment determination considering these developments. The lecture will also show how advanced instrumentation can help with the origin identifications.
Dr Matthias Krismer (Swarovski, Austria)
Responsible Sourcing and Marketing of Colored Gemstones: Challenges and Opportunities
Approximately 80% of coloured gemstones are produced by artisanal and small-scale mining operations in developing countries with weak governance structures. There is no internationally accepted due diligence standard and assessment procedure for coloured gemstones. With rising interest and expectations for socially responsible and ecologically friendly products, industry stakeholders and associations are working on processes and guidance to provide visibility of supply chains and sources. A few businesses, such as Swarovski, have started to work on traceable and responsible coloured gemstones supply chains from mine to market.
Dr Stefanos Karampelas (LFG Paris, France)
Coloured gems and natural pearls origin: The science behind
Several specific origins of gems (e.g., emeralds from Colombia, rubies from Burma, sapphires from Burma and Kashmir, natural pearls from the Arabian Gulf) are linked with history, exoticism, spirituality, etc., and might play an important role in the monetary value of a gem. Origin on gemmological reports are also sometimes used by dealers as a kind of brand name. In parallel ethical issues related to gem mining as well as legal vs illegal fishing and sustainability have been in the spotlight, and end consumers demand transparency on the supply chain. Origin determination for gems is also useful for archaeologists, curators, etc., as it can help them to better understand early trade routes. As a consequence, more gemmologists as well as persons from other industries and scientific sectors are interested. To perform (geographic or mollusc) origin determination non-destructively (or micro-destructively), the right instruments along with an extensive reference database and most importantly the right people with the relevant experience are needed. For sure, origin determination of gems and natural pearls has its limitations as geological (and biological) and political borders are rarely the same.