Marriot University Park Hotel , “Dessert” Meeting Room
880 E. 2 nd St ., Tucson , AZ 85719

February 3 2005 , 9:00 AM -12 NOON

“An Update on Gem Treatments & Enhancements”

Tickets available for US$30/person. Limited to 25 persons. Reservation is a must.

Veronica D. Themelis at veronica@themelis.com
In Bangkok call (66+2) 233-8805 or Fax (66+2) 237-5429

This seminar will enhance your knowledge and understanding on the new gem treatments. The seminar is prepared for the dedicated professional gemologist providing an updated overview on the ongoing gem treatment experiments and the latest methodology applied to ruby, sapphires, and other gems as performed in Ted Themelis's lab in Bangkok . This rare event will be presented by Ted in five separate PowerPoint presentations. Questions will be answered at the end of each session. The following topics will be presented:

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.
- Methods & procedures on second generation of beryllium-treatment process in ruby-sapphire.
- Latest treatments on jadeite, rubellite and other gems.
- Classification of gem treatments.

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.

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.

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.

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.