Pre-Conference Thessaloniki Tour

Workshops and Lectures

Cocktail party and Gala Dinner

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.

Speakers

Branko Deljanin

Branko Deljanin is President at CGL Canadian Gemlab in Vancouver. He is a research gemologist with extensive experience in advanced testing of diamonds and gemstones to determine origin of color. Branko is instructor of “Advanced Gemology” programs on diamonds and coloured stones offered in 17 countries on 4 continents. In 2001 he earned his Advanced Gemology Diploma (DUG) from the University of Nantes in France. He has been a regular contributor to trade and gemological magazines and presented reports at a number of research and gemological Conferences, including Mediterranean Gemmological and Jewelry Conference that he co-founded in 2015.

Elena Deljanin

Elena Deljanin, M.Sc., CGmA, FGA is a professional gemmologist with extensive experience in testing gems, colored diamonds as well as rough diamonds from different sources. She conducts research on the morphology of rough diamonds and is highly skilled in the use of traditional and advanced gem testing instruments. These include Visible and FTIR spectrometers which she has applied to diamonds from Canada, China, Brazil, Russia and Africa. She is considered an expert in the grading and classification of rough diamonds. Elena is instructor on “Rough diamond grading and evaluation program” in USA and Canada.

George Spyromilios

George, founder of I.G.L., is a Gemmologist and Jewellery Valuer. He is considered to be an authority in the Identification and Certification of Diamonds and Precious Stones in Greece. He is also an instructor holding Diamond Course and Coloured Stones seminars at IGL premises as well as at the Mediterranean School of Gemmology. Together with CGL Canadian Gemlab head gemmologist Mr. Branko Deljanin, George is a co-founder of the Mediterranean Gemmological and Jewellery Conference (MGJC).

Ioannis Alexandris

Mr. Alexandris is the founder and CEO of the Gemolithos Group of companies with offices in Munich, HK, London and Beijing. He is a gemologist and author specializing in antique jewelry at the high-end of the market. He has authored “Antique Jewelry 1800-1939” that will be published this year.

Jeffery Bergman

Jeffery Bergman is an American-born precious gemstone dealer and gemmologist with 5 decades of broad-based experience in natural gemstones, diamonds, and fine jewelry. Co-Founder and Director of Eighth Dimension Gems in Bangkok, Jeffery received his basic (BGC/BDC), advanced (ATC), and scientific (SGC) gemmological diplomas and certificates at SSEF in Basel, Switzerland. Jeffery is a frequent guest speaker at GIA Gem Gatherings, gemological conferences & universities, a regular contributor to gemological and other publications, Honorary Professor for the AIGS - Asian Institute of Gemological Sciences, and Vice President, Emeritus of the IGS - International Gem Society.

John Chapman

John Chapman has a degree in physics and has been active in the diamond industry for over 30 years mostly working for Rio Tinto Diamonds in a technical capacity. Since leaving the company he has been director of Gemetrix Pty which has developed and currently manufactures luminescence-based instruments to detect synthetic and treated diamonds and gems. More recently the company has developed a compact system for both PL and visible absorption spectroscopy. He is chief editor for the Mediterranean Gem and Jewellery Conferences and editor of Branko Deljanin’s 2021 book “DIAMONDS: Natural, Treated and Laboratory-grown”

Dr. Lore Kiefert

Dr. Kiefert studied mineralogy at the Mineralogical Institute of the University of Heidelberg, Germany, where she completed a master’s thesis on the origin of sapphires in 1981.

In 1994, she joined the SSEF Swiss Gemmological Institute as Deputy Director where she became Director of the Coloured Stones Department. She completed her FGA Diploma in 1998. In 2005, Dr. Kiefert moved to New York to head the AGTA Gemmological Testing Center as Laboratory Director and returned to Europe to join the Gubelin Gem Lab as Chief Gemmologist in 2009. In 2020, she opened her own consulting company.

Dr. Kiefert has authored and co-authored numerous gemmological publications in gemmological and scientific journals, as well as chapters in textbooks such as the Handbook of Raman Spectroscopy. Dr. Kiefert is also on the editorial review board of Gems & Gemology and the Journal of Gemmology.

Matthias Krismer

Matthias Krismer has been with the Swarovski Gemstones Business for 5 years and is responsible for the procurement of genuine and synthetic gemstones. He owns a PhD in geology from the University of Innsbruck and has done post-doc research on metal traceability, mining and its impacts on society and the environment. His teaching activities centered on mining and raw materials.

Dr. Michael Schlamadinger

Dr. Michael Schlamadinger is Head of Procurement for the Swarovski Gemstones Business. He graduated from the University of Graz in Mineralogy and Petrology in 1990. Additional to his role as a purchaser of rough and cut natural and synthetic gems, he has been in the market of man-made diamonds for well over 6 years.

Stefanos Karampelas

Dr. Stefanos Karampelas is Chief Gemmologist for the Laboratoire Francais de Gemmologie (LFG), the oldest gemmological laboratory in the world still in operation. He has experience as a Research Scientist for a period of seven years at Gübelin Gem Lab with a further year at Gem Research Swisslab, both in Switzerland as well as three years as a Research Director for the Bahrain Institute for Pearls and Gemstones. He is also a lecturer for the Advanced Gemmology Diploma at the University of Nantes, France, on pearls, laboratory methods applied to gems as well as origin determination of coloured gems. He has published numerous peer-reviewed articles in scientific journals, contributed to books, visited several gem mines and pearl farms around the globe. Stefanos is also frequently delivering lectures to international scientific conferences and gemmological meetings. He is a member of the Commission of Gem Materials of International Mineralogical Association, delegate for the International Gemmological Conference as well as member of the Editorial Board of the Gems and Gemology and Revue de Gemmologie de l'AFG and an Associate Editor of The Journal of Gemmology.

Travis Lejman

Travis Lejman, GIA GG, has been in the industry for 20 years. He is the second generation in his family and has recently taken over & continues to grow the company his father started in 1979. After receiving his BSc. from Stony Brook University in 2005, Travis continued on to graduate with his G.G. in 2006 from GIA New York’s residency program, and later going on to receive his F.G.A. accreditation from Gem-A in 2013. Over the last 6 years, Travis and his business partner, Joshua Lents, have added new advanced testing capabilities to their laboratory division.

Yianni Melas (Master Of Ceremony)

After graduating as gemmologist at GIA, Yianni became an instructor at GIA. Later, Melas began working for Swarovski as a rough stone buyer operating in several remote locations around the world. In 2004, after fourteen years at Swarovski, he joined the Lev Leviev Group, a leading diamond manufacturer. Through his work he sought to develop Botswana’s gem industry, with the belief that supporting an industry with business opportunities would help create jobs, and would allow self-empowerment to thrive. His concern for the welfare of Africans saw him stage a much publicised hunger strike in 2018. In 2015 he discovered a new blue green gem in Africa, which he named Aquaprase™. This year he is launching his trademarked jewelry brand, Yianni Melas™.

Workshops

Intermediate Gem Workshop

Lab on Opals: A Playful Array of Colors

August 12, Friday Morning (9:00 AM to 1:00 PM)

Instructors: Travis Lejman, FGA (GAL, NAJA, USA)
Assistant: George Spyromilios (IGL Greece)
Class Size: Max 30
Audience: For gemmologists, appraisers, and individuals with trade experience

This four (4) hour workshop is presented by Travis Lejman is based on Dr. Paul B. Downing’s system of grading and identifying opals.
We will start of in a lecture portion to get a base line down on opals. We will go over, types, formation, localities, treatments and properties on what to look for in grading and valuation. Quality of different types of opal and pricing would be covered. We will review items discussed in the book. Our hands-on section will look at 124 opal samples from around the world and of varying qualities.

What to bring: 10x loupe, pen light, tweezers, stone cloth, and a copy of Opal Identification & Value book by Dr. Paul B. Downing, Ph.D. If you don’t have it the book or a pen light, there will be some for sale. An OTT lights will be provided.

Venue & Schedule

This is the sixth in a series of annual conferences that will roam throughout the Mediterranean, allowing delegates to experience new and exciting locations each year.

The Met Hotel

26is Oktovriou 48
Thessaloniki 546 27,
Greece

Dear participants, please send an email to resv1.themet@chandris.gr and mention MGJ CONFERENCE, in order to get discounted price of the conference for hotel rooms.

THE MET HTL- ROOF GARDEN PORT VIEW NIGHT

Welcome to the 6th Mediterranean Gem and Jewellery Conference

Thessaloniki, Greece - August 12-14, 2022

The MGJ Conference is a ‘trade-technical’ conference that exposes current trade problems and offers solutions through workshops with standard and advanced affordable instruments. 75 participants from 27 countries attended the 2019 MGJ Conference in Cyprus. There are great reviews of MGJC 2019 in "IDEX Magazine", "The New Jeweler" (pages 100-101), and September's 'Journal of Gemmology'. The 6th annual MGJ Conference will be organized by CGL Canadian Gemlab and the main theme will be "ORIGIN of DIAMONDS and GEMS".

About Thessaloniki, Greece

Thessaloniki is the second-largest city in Greece. It is in the north of the country and is the capital of Central Macedonia. Thessaloniki’s rich cultural and historical heritage takes its visitors on a wonderful journey back in time. The city was founded in 315 BC (Hellenistic period) by King Cassander of Macedonia who gave it his wife’s and Alexander the Great stepsister’s name – Thessaloniki. City. Today, Thessaloniki is a dynamic city full of energy that honors and respects its history. Some parts of the city truly resemble outdoor museums, surrounded by Byzantine walls, countless Byzantine churches, and monuments of times long gone. However, it also boasts pedestrian streets with top fashion houses, boutiques, and exquisite local cuisine that tempts connoisseurs and those looking for its famous nightlife! The promenade along the waterfront and the elegant cafes are just minutes away from the hotel.

Tours

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Thessaloniki City Tour (Half Day Tour)
Thursday, August 11th

Tour will give you the opportunity to admire the castles (Ano Poli - Upper Town), visit the Byzantine church of Agios Dimitrios, see the Arch of Galerius (Camara) and the Rotunda, the White Tower, the statue of Alexander the Great and the historical centre, the Archaeological Museum (ticket included) and the Serbian, Greek, Russian, French, British and Italian cemetery from World War I, Zeitenlik, the largest military cemetery in Greece. Afternoon tour from 13:00 to 18:00 including bus and English speaking guide.

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Mount Athos Cruise (Full Day Tour)
Monday, August 15th

Mount Athos, also known as the "Virgin Mary's Garden", is internationally recognized as a holy land for Christian Orthodox faith. An independent monastic state inhabited by monks for more than a thousand years, observing the rules of the Church and the Byzantine traditions. The pirate boat takes you on a journey in time, along the shores of Mount Athos, where you can admire the unique scenery and magnificent architecture of the monasteries. You will have the opportunity to see eight monasteries, on the west coast of the Athos peninsula, listen to its unique history and, if you are lucky, also see many dolphins! The route includes a stop in beautiful Ouranoupolis, for lunch or a swim.

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North Macedonia Gem Tour

Marble and Pink Sapphire Mine at Prilep, Skopje, August 16th

The group will leave at 8.30 am from the Hotel Mediterranean by mini-bus heading north to Prilep and to a nearby marble deposit at Sivec where is big world class marble deposit corundum crystals are mined as by-product. A guided tour of the mine will be given and a visit to a mineral exhibition. Lunch will be at a local restaurant in Prilep with traditional local specialties. In the afternoon, there will be a 1.5 hr drive to Skopje with some sightseeing of the town in the afternoon. Dinner will be in a restaurant at a 4-star hotel with live music.

Geology: Rubies from the neighbourhood of Prilep (North Macedonia) are found in marbles belonging to the central part of the Pelagonian Massif. They have been formed through metamorphism of carbonate rocks. The main mine of rubies is the Sivec Quarry, which is situated 8 km northwest from Prilep at the foot of Sivec Hill and in which high quality and often completely snow-white dolomitic marble is extracted. Special attention has always been drawn by specimens of corundum and diaspore visible to the naked eye, and other accompanying minerals such as fluorite, rutile, micas, dolomite, zoisite, achroite, pyrite, muscovite, illite, margarite, chlorite and kossmatite.

In the dolomitic marble, corundum as a mineral is bound to calcite nests. Morphologically, they are diversely shaped and can develop flat, barrel-like, prismatic and even rhombohedral crystals.

Gemmology: They are usually light pink, less often intense red, while the rarest are blue. The pink to red colour of the Prilep corundum is influenced by the mixture of chrome, vanadium and iron, whereas the blue colour is influenced by titanium. Owing to these mixtures, particularly chrome and vanadium ions, the corundum of Prilep dolomitic marble fluoresces red, orange and yellow.

Diaspore in corundum crystals is oriented in three directions intersecting at 60 degrees, resembling an asagenite-like structure. The characteristic silvery glittering of diaspore in corundum is most intense in the direction of the rhombohedron faces. Diasporescence is a kind of silvery glittering, which is manifested as a white reflection on the surface of a cabochon and has been classified as an optical phenomenon. Oriented intergrowth of diaspore and corundum affects gem density, as diaspore has a lower density than corundum. Rubies of the Prilep dolomitic marble thus have a density ranging from 3.53 to 3.93 g/cm3, which is less than the density of rubies (3.97 to 4.05 g/cm3) and more than the density of diaspore (3.39 to 3.40 g/cm3). Rubies from Prilep have been described in professional gemmological literature very rarely, or just individual data are given for their physical characteristics. It is interesting that diaspore is not described as an inclusion in rubies from other localities. This means that diasporescence is not only a new optical phenomenon in the world of gemstones, but also an optical phenomenon that indicates the origin of rubies being from the Sivec Quarry.

References

Diasporescence of rubies from Prilep dolomitic marble by Miha Jersek, Slovenia Museum of Natural History, Slovenia, Proceedings of 4th MGJ Conference, Budva, Montenegro, 2018, pp 36.
Corundum from Prilep Dolomitic Marble (North Macedonia) by Miha Jeršek & Breda Mirtič, SCOPOLIA, Journal of the Slovenian Museum of Natural History, Ljubljana, No. 41, September 1999, pp. 1–22

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Serbia Mineral and Cultural Tour

Wednesday to Saturday: August 17-20, 2022

Geological Wonder, Hot spa Lukovo, Mountain Kopaonik (August 17th)
Winery, Orthodox Monastery, Serbian Royal House (August 18th)
Lead and zinc mine Rudnik, mineral collecting, Belgrade by night (August 19th)
Tour of Serbian capital Belgrade, mineral museum (August 20th)
Winery at Fruska Gora mountain, Petrovaradin tower at Novi Sad (August 21st)
Transport to Belgrade airport (August 22nd)

Geological Wonder, Hot spa Lukovo, Mountain Kopaonik (August 17th)

Visit to Devil’s Town (‘Djavolja Varos’), a peculiar rock formation created by erosion and two springs of extremely acidic water with high mineral content.

Lunch in typical Serbian village Brzece with local organic specialties like ‘kajmak’ – cheese spread. Kopaonik, the largest mountain range in Serbia is especially beautiful for its distinctive landscape of spruce and fir forests at higher elevations and mixed beech and oak forests on its slopes, and meadows and 2000m+ peaks with spectacular views. Lukovo Spa is characteristic for its large number of mineral springs, indoor and outdoor pools with thermal water and modern medical and wellness treatments, untouched nature of the wooded Kopaonik and clear mountain air.

Lukovo spa – dinner with live music and accommodation on a dinner and breakfast basis in hotel Jelak.

Winery, Orthodox Monastery (August 18th)

Trip along “Valley of Lilac” to the medieval monastery Zica.

Two hours’ drive through central Serbia region called ‘Sumadija’ (meaning ‘forest area’), the spiritual and cultural capital of Serbia. Here trumpets and pipes provide musical entertainment, the ‘kolo’ dance weaves in and out at major gatherings.

Visit to Oplenac St George’s Church & mausoleum of the Serbian royal house Karađorđević. Visiting vineyards with degustation and cheese at Topola.

Accommodation on a dinner and breakfast basis in a hotel.

Rudnik Mine, Belgrade by night (August 19th)

Visit to lead, zinc mine ‘Rudnik’, learn on “flotation process” to extract minerals from ore and hunt for minerals in the region.

Continue north to Belgrade. Dinner in Belgrade at “Splav” restaurant on the water where Sava meets Danube, with live music.

Accommodation on breakfast basis in a hotel “Bahus” in Belgrade.

Serbian capital Belgrade (August 20th)

Sightseeing in Belgrade by tourist bus! Belgrade’s most significant landmark is the ‘Kalemegdan’, an imposing fortress at the confluence of the Danube and the Sava rivers. The fort is testimony to the city’s strategic importance to the Roman, Byzantine, Ottoman, Austrian and Serbian empires, and it’s now the site of several museums as well as a vast park.

Lunch at a typical “kafana” restaurant in the city center.

Winery at Fruska Gora mountain, Petrovaradin tower at Novi Sad (August 21th)

1.5h drive to Fruska Gora in Vojvodina province that was under Austrian Hungarian Empire until 1st world war. Visit to famous vineries at Sremski Karlovci, and orthodox church dedicated to the Saint Nicholas, and Roman Catholic church dedicated to the Holy Trinity. Lunch with fish soup at Petrovaradin fortress overseeing Danube and Novi Sad, provincial capital.

Transport on to the airport for flight back home (August 22th).

Intermediate Diamond Workshop

ID and Grading of Treated Synthetic and Natural COLOURED Diamonds, loose and mounted with Standard Instruments

August 12, Friday Afternoon (2:00 PM to 6:00 PM)

Instructor: Branko Deljanin (CGL Canadian Gemlab, Canada)
Assistants: George Spyromilios (IGL, Greece)
Class Size: Max 30
Audience: For gemmologists, appraisers, and individuals with trade experience

BROWN, YELLOW and ORANGE diamonds: sources/producers, characteristics and ID
GREEN and CHAMELEON diamonds: source/producers, characteristics and ID
BLUE diamonds: sources/producers, characteristics and ID
PINK/RED diamonds: sources/producers, characteristics and ID
Use of Standard Instruments to separate Coloured Natural and Synthetic Diamonds
Color Enhancements – stable (irradiation, annealing, HPHT, multistep treatments)
Post treatments of HPHT-grown and CVD-grown diamonds (irradiation)
Identification methods for treated diamonds with advanced instruments at labs
Grading and Certification of coloured diamonds at gem laboratories
PRACTICAL WORKSHOP: Coloured Diamonds are graded with Munsell book of colour and master set, tested with portable polarioscope/portable light, screening with PL Inspector and microscope and ID with advanced instruments

Gem Workshop

’GEM Country of Origin WORKSHOP’ by Lore Kiefert (Gemmological Consultancy Company, Germany)

August 13, 2022 (Saturday), 9:00 AM to 2:00 PM

Instructor: Lore Kiefert (Gemmological Consultancy Company, Germany)
Assistant: Branko Deljanin (CGL Canadian Gemlab, Canada)
Class Size: Limited to 12 seats, first come first serve basis
Audience: For gemmologists, appraisers, and individuals with trade experience”

This workshop concentrates on the ‘major three‘ – Ruby, Sapphire, and Emerald: unheated and low temperature heated samples of ruby and sapphire, as well as filler detection in emerald. Inclusion photos of the most important origins will be presented, together with samples for microscopy. Due to time constraints, Ruby will be restricted to Burma (Mogok, Mong Hsu), Thailand and Mozambique, Sapphire to Burma, Sri Lanka, Madagascar and magmatic origins, and Emerald to Colombia, Zambia (Kafubu), and Ethiopia. Inclusions from gems from other origins will be mentioned, and overlaps pointed out.”

PRACTICAL WORKSHOP: Inclusions in Coloured Gems from different countries will be tested with microscopes, fluorescence with portable PL Inspectors, and PL/Fluorescence spectroscopy with EXA advanced instrument”.

Advanced Diamond Workshop

ID of Treated Synthetic and Natural COLOURLESS Diamonds, loose and mounted with Standard and Advanced Instruments

August 14, Sunday Morning (9:00 AM to 1:30 PM)

Colourless Natural diamonds: sources, characteristics and identification
Methods of growing HPHT and CVD diamonds
Inclusions in Natural and Synthetic diamonds
UV lamp – reaction of different diamonds, loose and mounted with “PL / Jewellery inspectors”)
CPF (Cross Polarized Filters) method and instrumentation to screen and ID diamond’s origin
Clarity and Color Enhancements – unstable (Fracture Filling and coating),
Clarity Enhancements – stable (Traditional Lasering, KM Laser drilling)
Post treatments of CVD-grown colorless diamonds (HPHT)
ID of HPHT-enhanced diamonds using advanced instruments
ID of mounted synt. diamonds with EXA instrument and screening instruments
Problems and solution in identification of melee natural and synthetic diamonds

PRACTICAL WORKSHOP: Samples of Ia, IIa, IIb, Ib diamonds (natural synthetic origin) are tested with microscopes, mini UV lamp (“PL inspector”) and Mini Polarioscope with Portable light and advanced instrument EXA Natural diamond detector.