Ted Themelis offers presentations and seminars to professional gemological and jewelry organizations as well as to private groups and company executives focusing on gem mining, treating, trading, and related topics.

Our first seminar was given in 1986 in Tucson (GLDA gem trade show) on the heat treatment of Sri-Lankan ruby-sapphire and ever since more than 80 seminars, presentations and workshops on diversified gemological topics have been held in the USA, Germany, France, UK, Greece, Italy, Brazil, Burma, Thailand, Hong-Kong, Singapore, and elsewhere. Sponsors of these events include Gemmological Association of Great Britain, American Gem Society, Gemological Institute of America, Gemmological Society of Singapore, National Association of Jewelry Appraisers, International Society of Appraisers, CIBJO, Gemmological Association of Hong-Kong, Greek Gemmological Association, Austrian Gemmological Association and others.

Presentations may be given to the audience in simple PowerPoint sessions or they might be held in workshops where small groups of participants examine gemstones in "hands-on" schemes aided with gemological instruments.

Ted at the IGI conference in China where he delivered his latest work on LIBS (Wuhan, China, Sept. 2004)

Ted presented a workshop on the beryllium-treated rubies-sapphires to the members of the Hong-Kong Gemmological Association (Bangkok, Oct.18, 2004).

Ted presented an updated seminar on the latest developments in the heat-treatment of ruby-sapphire. More than 40 gemologists attended (Tucson, Feb.3 2005)

Ted presenting a special seminar on gem treatments (Bangkok, Feb. 17, 2005)

Ted presented his latest work and update on beryllium-treated gems, glass-filled rubies, LIBS and other topics. His presentation in Milan was attended by more than 150 gemmologists. (Milan, May 29, 2005)

Ted addressed the beryllium-treated sapphire problem at the Orange Sapphire Club attended by gem dealers, gem treaters from Bangkok and Chanthburi (Bangkok, Dec. 2004)

May 29,2005:ITALIAN GEMMOLOGICAL INSTITUTE, Milan,Italy
At the occasion of the 20th anniversary of the Collegio Italiano Gemmologi (IGI) on May 29, 2005, the following program was presented by Ted Themelis in PowerPoint and "on-hands" practical sessions:
SESSION-1. BERYLLIUM-TREATED RUBIES & SAPPHIRES. First and second generation on the beryllium treatment techniques and methodology in corundum. Affiliated additives used in the process. Characteristic inclusions and other gemological features. Identification of the Be-treated corundums using SIMS, LA-ICP and LIBS methods. Materials: Several sets of beryllium-treated rubies & sapphires before-after the beryllium treatment from different localities will be shown.
SESSION-2. ROMANCING THE GEUDA. A very rare documentary videotape (25 minutes) shown in detail the heat-treatment of geuda sapphires in Sri-Lanka will be presented. The video was taped in Ratnapura in 1985 by Ted Themelis. Geudas will be shown before and after treatment followed by discussion and comparison of the treatment techniques practiced today in Thailand and Sri Lanka.
SESSION-3. LEAD-FILLED RUBIES. The newest treatment of filling rubies with lead, bismuth and other oxides will be discussed as practiced in Thailand. Methodology, heat-treatment techniques, gemological aspects and related topics will be discussed in detail. Materials: Sets of Pb-filled rubies with characteristic inclusions will be shown.
SESSION-4. GEMS OF MOGOK. An update on gem mining and gems of Mogok (about 45 species) will be presented based on 11 field trips taken by Ted Themelis from 1997 to 2004 at Mogok. This is the first complete presentation on Mogok gems where several new gem species will be included for the first time.

For further information please contact:
Gianfranco Saccucci (Collegio Italiano Gemmologi): info@collegio-gemmologi.it

Feb. 3, 2005: TUCSON 2005 SEMINAR PROGRAM, TUCSON, USA
The following program was presented by Ted Themelis in a special seminar at the Marriot University Hotel (Tucson).
SESSION-1. An update of the currently practiced gem treatments.
- The role and effect of Pb, Bi and other “heavy” elements mixed with Be, Li and other “light” elements in heating ruby-sapphire.
- Second generation of methods & procedures on Be-treated ruby-sapphire.
- Latest treatments on jadeite, rubellite and other gems.
- Classification of gem treatments.
SESSION-2. LIBS in gemology. Problems and proposed solutions in detecting beryllium in corundum using the Laser Induced Breakdown Spectroscopy (LIBS) method. Beryllium calibration curve in corundum, tolerance of error, specimen damage, effect of the “master” comparison Be-treated samples and other issues will be discussed. Beryllium-treated sapphires and subsequently tested with LIBS will be shown.
SESSION-3. Review of the “geuda” treatment.
- An overview on the most commonly practices used in heat-treating “geuda” corundums in Thailand and Sri-Lanka. Classification of “geuda” types, treatment methodology, furnaces used in the heating of “geuda”.
- A very rare video-tape on the “geuda” treatment filmed by Ted Themelis in August 1988 (20 minutes) will be shown.
SESSION-4. Lakmini and Lakmaxi. Presentation of the second generation of “lakmini” and “lakmaxi” gas-LPG furnaces and its practical application in heating corundums as currently practiced in Sri-Lanka and India . Rubies-sapphires before/after heating using the “lakmini” furnace will be shown.
SESSION-5. Gas combustion and electric furnaces in heating ruby-sapphire.
- Advantages and disadvantages using combustion and electric resistance furnaces.
- Features of the newly-designed GEMLAB 1800 o C electric resistance furnace and its applications in heating ruby-sapphire.
SESSION-6. Cost effectiveness in heating ruby-sapphire.
- Case study: Anatomy and analysis of three failed companies involved in the heat-treatment of ruby-sapphire.
- Avoiding the pitfalls of the "scientific" gem treatments and face the reality.