2026 AGA Tucson Gemological Conference and Gala

Sarah Caldwell Steele fell in love with Whitby jet at age seven and hasn’t stopped cutting or challenging assumptions since. With four decades of lapidary experience and a Durham geology degree, she’s the world’s leading jet authority.

A Fellow and Diamond Fellow of the Gemmological Association of Great Britain, Sarah specializes in black gem identification and commercially cuts jets, amber, ivory, and other organics. Currently a Durham PhD researcher, she’s developing revolutionary methodology for identifying carbonaceous archaeological artifacts.

Sarah’s mission: establish new nomenclature for gem-quality hydrocarbons and challenge outdated jet classifications. Her research bridges geology, gemmology, and archaeology—proving jet isn’t just a mourning stone, it’s a portal to the past.

Whether teaching gemologists to “see in the dark” or rethinking ancient gem classification, Sarah aims to bring clarity to gemology’s most misunderstood materials.

Kerry has a one track life*. She’s a gemologist. It’s her job, her passion, and her hobby. She doesn’t do much else!(*full disclosure she does also enjoy good wine, great food, close friends and pub quizzes.)

She spends her time exploring gemology, playing with it, questioning it. She even spends most of her “holiday time” traveling with other like minded friends, often wearing a tiara, whilst seeking out gems and jewelry and licking rocks (she’s been told to stop the rock licking but does it anyway). Always striving to find ways to improve her practice. Along with discovering new ways to help others learn more, in fun accessible and engaging ways.

Kerry is known for her fast paced and funny presentations, and practical hands-on workshops that get right to the point of what you need to learn. She has delivered presentations and workshops, to critical acclaim, to many organizations and associations including; The National Association of Jewellers (UK), The National Association of Jewelry Appraisers, The American Gem Trade Association and Gemworld International. She has had numerous articles on practical gemology published in both UK and US publications.

A past long term tutor and head of ATC for Gem-A, she served on the board of Gem-A, and ran one of the UK Branches. Currently on the Board of Trustees for the Silversmiths and Jewellers Charity (UK), and a key contributor to the National Association of Jewellers (UK) Professional Trade Standards Committee, particularly focusing on Gemstones, Diamonds and Hallmarking practices. Kerry is also a Freeman of the Worshipful Company of Goldsmiths and the City of London, and the most recent appointee to the British Hallmarking Council committee.

Damien Cody is Managing Director of Cody Opal (Australia) and The National Opal Collection.

He is the current President of the International Colored Gemstone Association (ICA) having served many years in various positions including Vice President, Director and Ambassador to Australia.

He has also served on various industry Boards and committees including CIBJO, the Opal Association, the Jewellers Association of Australia (JAA) and The National Opal Miners Association.

He was the founding Chairman of ICA’s charity ‘Gems Keep Giving’ and is currently serving as Acting Chairman of the newly formed independent Board.

He is co-author of a top-selling book ‘The Opal Story’ which has been written in five languages. Around 60,000 copies have been sold and distributed around the globe.

In 2018, his company produced a limited release of sixty opal master sets. Each set contains 216 opal samples from all of the world deposits to assist with identification, classification and grading of opal. Most major laboratories and gemological institutes have availed themselves of this resource. This initiative earned Cody Opal Australia a JNA Honoree award for Industry Innovation of the year.

In 2023 Damien’s industry achievements were recognized by being selected as a recipient of an ‘Extraordinary 40 Award’, a Jewellery World Awards (JWA) accolade presented to 40 inspiring individuals whose talents, achievements and commitment to excellence have helped shape and continue to make a positive difference in the Jewellery industry today.

Dr. Clemens Schwarzinger is associate Professor for chemistry at the Johannes Kepler University Linz, Austria. In 2016 he founded the Center for Scientific Gemmology at the University Linz and is scientific advisor of the Viennese Diamond Bourse. He is owner of a small company which is dedicated to precision gemstone cutting and developing novel cutting designs. In 2017 he won the US Faceters Guild Single Stone competition in the Master category, in 2018 and 2019 he was certified as Grand Master. In 2021 he was winner of the Gem A Photo Competition and in 2024 he received the Gemological Research
Grant from the AGA.

His academic research interests (in terms of gemology) focus on the identification of gem treatments and mineral chemistry, particularly on the use of trace elements in combination with statistical tools for origin determination of garnets and the coloration of zoisies/tanzanites as well as the use of advanced spectroscopy techniques. He is author of more than 90 scientific papers, Co-host of the educaional online program “GemQuest” and gave hundreds of oral and poster presentations. The passion for gems arose from being a lifelong collector of minerals with an emphasis on gem species.

Dr. Aaron Palke developed an interest in minerals and gemstones searching for agates and other minerals in eastern Montana. He was particularly struck by the geographic distribution of mineral and gem deposits and geological features, for instance, why were there mountains and an abundance of mineral deposits in Montana but not in his home state of Oklahoma? These questions led Dr. Palke to pursue a formal education in geology, obtaining a Bachelor of Science degree from The University of
Tulsa and a Ph.D. from Stanford University.

Dr. Palke began his gemological career as a Postdoctoral Research Associate at the Gemological Institute of America where he is now the Senior Manager of Colored Stone Research. In this role, Dr. Palke leads GIA’s research efforts into geographic origin determination for rubies, sapphires, emeralds and other colored stones as well as improving criteria for identification of treatments for colored stones. Dr. Palke is a regular contributor to Gems & Gemology, serves on the journal’s editorial review board, and has acted as a Guest Editor for two special issues of the journal so far.