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.
Adeline Lageder (Gemmologisches Labor, Austria)
Dr Vera M.F. Hammer (Natural History Museum Vienna, Austria)
Historic diamond rings from the Natural History Museum Vienna – Appraising the “invaluable”…
To date, the top five most expensive jewels ever sold at auctions are coloured diamonds. Making diamond-grading reports of historic items in museum collections is necessary, not for sale reasons but amongst other purposes, for insurance when lending them for exhibitions. An investigation was made of twenty rings in the Natural History Museum Vienna set with natural coloured diamonds (blue, pink, green, brown and yellow), acquired in the 18th and 19th century. Only some stones were labelled with their origin – India, East India or Golconda. These diamonds were analysed, including diamond type and grading. The different shapes of cuts could be best shown using electron microscopy.
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.
Gina D’Onofrio (Heritage Auctions, USA)
Appraisal Report Challenges
Why does the same diamond have multiple values? As appraisers we are asked to provide an appraisal but the client is completely unaware that the value is tied to how the information is to be used. The price of a diamond in a luxury retail store is dramatically different to the price that the exact same diamond will sell for in the secondary market. A professional appraiser will take the time to understand and explain this to their client and describe the intended use and market clearly in the report. Appraisal services and report writing is an important service that private clients, banks, attorneys, estates, government bodies and insurance companies rely upon. Understanding how your appraisal report will be used will help you write a report that is relevant and not misleading. What steps are involved when appraising for liquidation? Is it the same as for Insurance coverage? How much research is enough? What education and resources will prepare you for challenging appraisal assignments?
We will explore these and many other questions when dealing with appraisals for liquidation, insurance, estate distribution, divorce and litigation.
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.
Jeffrey Bergman (8th Dimension 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.
Kelly E. Hassen (Gemometrics, Sweden)
GemPen ® Applications
Appealing to eco-friendly consumers, it is no longer a question of ‘if’ but ‘when’ you will encounter a lab-created diamond. Will you know when you do? Do you have the equipment and training to differentiate between natural and lab-created diamonds? Could you distinguish an HPHT lab-created diamond from a CVD diamond? In an industry built on trust, lab-created diamonds present a very real challenge, testing not only the credibility of the seller but also how we can protect the end user. Developed by Gemometrics AB, GemPen ® utilizes USOF (Ultra Spectrum Optical Filtering) technology to detect lab-created gemstones and treatments that exhibit fluorescence and phosphorescence but are typically difficult to detect with other UV-light products. We will also review the broader use of GemPen ® and the continued research Gemometrics is doing in the detection of lab-created rubies and blue sapphires and the common treatments (heat, diffusion and cobalt-doped glass fillings) used to enhance their appearance and value.
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 Olga Okhrimenko (Octonus, Finland)
Maximising diamond appeal: New digital aid to launch an irresistible cut
There is no general industry agreement on how to judge performance of fancy diamond cuts. Thus, a chance to effectively design and promote, for example, a new star cut is quite limited. A new technology based on computer-aided simulations allows one to check what cut variants appeal to consumers and to develop internal customised digital reference sets. This approach follows the proven ‘MAYA Principle’ for the development of new designs, promotes positive changes in the industry and endorses product development, which is critical for the industry’s sustainability. In contrast, the current practice doesn’t support many types of cut changes relying on the belief that existing “ideal” cut designs cannot be improved. Additionally, the technology can be used for remotely sorting, selecting and quality control checks of polished diamonds and it can be performed by less qualified personnel than currently. A match against a reference range guarantees product consistency and end users’ satisfaction.
Reuven Paikin (Almod Diamonds, USA)
Crown of Light Cut
Almod Diamonds Ltd, is entering its 4th decade as a vertically integrated business via mining, rough manufacturing, jewelry manufacturing, marketing and retailing of gems and jewels. The company developed the ‘Crown of Light’ cut in 2007 featuring 90 facets to create increased light return and performance. The light performance of the Crown of Light cut has been studied by Dr. Jose Sasian of the College of Optical Sciences, University of Arizona who found increased light return, As the cut matures, the ‘Crown of Light’ is expanding into other areas of the gem and jewelry market.
Dr Stefanos Karampelas (Bahrain Institute for Pearls and Gemstones, DANAT, Bahrain)
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.
Dr Yuri Shelementiev (Moscow State University, Russia)
The importance of diamonds and coloured stones origin – methods and practices
Origin is a hot issue today both for diamonds and coloured stones. Country of origin determination for coloured stones is based on gemmological analysis while diamond origin is mainly based on tracking with documentation from a mine to customer. The diamond tracking technologies of De Beers, Alrosa, Sarin, GIA, Tiffany and Chow Tai Fook are compared; and the influence of origin on customers is examined. The origin determination of coloured stones is based on microscopy, spectroscopy and chemical analysis; and recently a ‘DNA analysis’ including determination of geological age is being offered by SSEF and Gubelin labs. The market is changing as the old ‘brand’ deposits are depleted and new deposits are discovered. Thus origin creates selling stories for diamond and coloured gems. Also in recent years the demand for origin has not been not limited to the classical big three: emeralds, rubies,and sapphires. Today there is demand for origin for other gems such as paraiba tourmaline, demantoid, spinel, opal and pearls.