Following the success of the Mediterranean Gem and Jewellery Conference 2024 in Italy and Slovenia, organized by Branko Deljanin, the gemological world is gearing up for another major event: the 2nd GemConference, set to take place from June 13 to 15, 2025, in Helena, Montana (USA).
The event combines hands-on workshops on gem identification and trade with the exploration of unique mining sites, reinforcing its role as a key meeting point for international experts, gemologists, collectors, and enthusiasts.
Workshops Featuring Over 200 Global Specimens & Seminars Led by World-Renowned Experts
GemConference 2025 will offer a high-level program featuring seminars and workshops led by some of the most esteemed experts in the gemological
Workshops:
“Treatment and origin determination of sapphires” – June 13, 9:00 AM – 5:00 PM (Friday)
Dr. Lore Kiefert (Germania)
A workshop dedicated to microscopic methods for detecting treatments and inclusions in sapphires from various sources. Techniques include UV fluorescence, UV-Vis, and FTIR spectroscopy. Participants will have access to over 50 sapphire specimens, many accompanied by photomicrographs of typical inclusions.
“Turquoise Workshop” – June 15, 9:00 AM – 12:30 PM (Sunday)
Joe Dan Lowry (USA)
An interactive session on the history, availability, imitations, and valuation of turquoise. With a hands-on approach, participants will learn how to classify turquoise and identify common market imitations.
“Screening and ID of Synthetic & Post-Treated Diamonds” – June 15, 1:30 PM – 5:00 PM (Sunday)
Branko Deljanin (Canada)
A practical workshop for jewelers and appraisers focusing on HPHT and CVD diamond identification using portable instruments and advanced screening methods. Participants will practice identifying CVD lab-grown diamond patterns using polarized filters and UV lamps.
Seminars:
“Rock Creek Sapphire Mine”
Warren Boyd, Potentate Mining (USA)
A look into the historic Rock Creek sapphire mine (active since 1892), covering its geology, location, mining methods, and recovery techniques.
“Origin Determination of Sapphires”
Dr. Lore Kiefert, Gemmological Consultancy (Germany)
This seminar explores one of the most challenging aspects of gemological laboratories—determining the origin of sapphires. The discussion will focus on the microscopic properties of sapphires from regions such as Burma, Kashmir, Sri Lanka, Madagascar, Thailand, Cambodia, and Australia. Additional advanced methods like UV-Vis, FTIR, EDXRF, and LA-ICP-MS will also be covered.
“Turquoise 101”
Joe Dan Lowry, Turquoise Museum (USA)
A deep dive into the world of turquoise, including evaluation, classification, and common imitations.
“Gem Secrets: The Importance of Inclusions & CPF”
Randall Lightfoot, Mayflower Estate Buyers & Consulting (USA)
A seminar on how photomicrography revolutionized gemology, focusing on inclusions as indicators of natural origin, treatments, or synthetic imitations.
“Screening Instruments for Laboratory-Grown Diamonds”
Guy Borenstein, Stuller (USA)
An overview of synthetic diamonds’ rising market presence and the latest screening technologies—their capabilities, limitations, and blind spots.
“An Update from GCAL by Sarine Lab: Diamond Traceability, AI-Driven Grading, and Market Dynamics”
Sharrie Woodring, GCAL (USA)
A look at diamond traceability, AI-enhanced grading, and the impact of U.S. sanctions on diamond sourcing.
“How India’s CVD Boom in Production, Treatments, and Cutting is Reshaping Diamond Mining and Gemological Testing Worldwide”
Branko Deljanin, Gemmological Research Industries (Canada)
Insights from a recent visit to Surat, India, highlighting the CVD diamond boom and its impact on global gemological practices.
Legendary Mines & Spectacular Gems
One of the exclusive highlights of GemConference 2025 is the opportunity to visit Montana’s most famous sapphire mines, offering a firsthand experience of American geology.
Mine Tour 1: Yogo Sapphire Mine (June 11–12)
A rare expedition to the Yogo Sapphire underground mine (Roncor Inc.), known for its exceptionally deep blue, naturally flat-cut sapphires. Limited to 20 visitors.
Mine Tour 2: Missouri River Deposits (June 12, Half-Day)
A visit to Spokane Bar along the Missouri River, home to some of Montana’s largest and most valuable sapphires.
Mine Tour 3: Rock Creek – Potentate Mining (June 16–17)
A unique chance to witness sapphire extraction and processing at one of North America’s most active mines (operating since 1892).
Tour 4: Yellowstone National Park (June 17–18)
Not just gems! The final day will be dedicated to exploring Yellowstone National Park, featuring geysers, forests, and incredible wildlife.
