We are proud to have world leading independent lab gemologists, gem dealers and experts as speakers and instructors.
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, 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, 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).
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 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 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 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.
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, 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™.