Contact us via e-mail
Click here to return to Home.



  COURSE # 610

    - Description

    - Syllabus

   - Student Comments

   - Class Photos

   - Alumni Photos

  COURSE # 999



SYLLABUS - COURSE #610: Ruby-Sapphire Treatments
Course #610 is intense and interactive, covering most issues in ruby-sapphire treatments. During the course, (and at the most appropriate occasion), the following will be presented and performed by all participants:
  • About 60 Power Point presentations conveying the principals and definitions in gem treating technology and methodology
  • Video clips on heating rubies-sapphires as performed in Thailand and in Sri-Lanka
  • Demonstration of the the most sought heating processes of blue sapphire using the gas combustion LAKMINI furnace; for ruby, demonstration of electric resistance furnaces (Gemlab models M50, M76, M80).
  • Demonstration of treatment processing equipment: instruments, heating elements, ceramics; chemicals and related materials will be provided (not to be taken out of the class)
(lab session-gem examination)
Lab sessions include examination of hundreds of untreated-treated rough/cut rubies-sapphires from Burma (Mogok, Mong-Hsu), Madagascar, Mozambique, Tanzania (Umba, Songea, Tunduru, Morogoro, etc), Australia, Nigeria, Congo, Guinea, China, Colombia, Brazil, Sri Lanka, Tajikstan, Nepal, India, Ethiopia, Thailand (Borai, Bang-kha-cha, Kanchanaburi), Laos, Cambodia, Vietnan, and elsewhere. Also, examination of treated synthetic ruby-sapphire; color-asterism surface diffusion on natural-synthetic ruby-sapphire, etc.
(lab session-gem treatment)

Practical on-hands sessions on treatment runs of ruby-sapphire to be performed by all students:

  • PROCESS #1 (HEAT-flux and no flux). Heating selected rubies and pink sapphires from Mozambique, Vietnam, Madagascar, Tanzania, and elsewhere. Prepare and execute a heating process using gas fugacity with/without fluxes.

  • PROCESS #2 (HEAT-beryllium): Heating select, rubies-sapphires from Songea, Madagascar, Tunduru, Mozambique and elsewhere. Prepare and execute a "dry" beryllium heating process using a high-temperature electric furnace.

  • PROCESS #3 (HEAT-low-temp. no flux): Heating selected rubies-sapphires from different localities using a low-temperature furnace with/without additives

  • PROCESS #4 (FRACTURE FILLING): Perform the oiling process of rubies-sapphires

NOTE: Due to time limitations and other restrictions, the actual "Lead-filling" process of ruby will not be performed; however, the related preparation and application process will be discussed in detail.


  • Understand corundum as an imperfect crystal
  • Review the fundamentals of heat and the effect of heat in gems
  • Comprehend temperature measurement (types, description, calibration)
  • Learn the concept of oxidizing-reducing atmosphere, buffering & non-buffering reactions, gas fugacity
  • Comprehend the influence of gas fugacity in heating gems
  • Master the muffle concept and how to obtain precise gas mixtures
  • Understand gas technology and gas mixing methodology
  • Learn the concept of diffusion phenomenology and differentiate the different types of diffusion
  • Be familiar and work with different types of ceramics used in gem treating processes
  • Understand the various types of gem treatment equipment
  • Learn the various gem treating processes and equipment as practiced in the commercial market:
  • Heating, Filling, Irradiation, High-Pressure-High Temperature (HPHT), Impregnation, Bleaching, Coating
  • Review briefly the historical aspects in heating ruby-sapphire
  • Recognize the various types of treatments of ruby-sapphire
  • Plan the strategy in heating ruby-sapphire
  • Learn about additives and fluxes: methodology, application, safety & handling, how to prepare and apply flux-melt additives and reagent-grade powers for heating ruby-sapphire
  • Develop the skills in understanding the heat-treatment processes of ruby, pink, "padparadscha", orange, yellow, purple/violet, sapphire, yellow, blue, blue/green, green and star sapphire
  • Become skilled in setting up the heat-treatment parameters in heating ruby-sapphire
  • Learn how to prepare and run a heating process
  • Learn about and examine the anatomy of open-flame furnaces (traditional kilns, i.e.coke, lignite, diesel-oxy furnaces, LPG-OXY, etc.) used in heating ruby-sapphire
  • Watch a rare documentary videotape "Romancing the Geuda" in heating geuda sapphires filmed in Sri Lanka by Ted in 1985; other documentaries
  • Learn the "dry" and "wet" beryllium heating processes of ruby-sapphire (methodology and processes of different types of corundum, inclusion features, handling-safety, stability, disclosure)
  • Comprehend the LIBS method in detecting beryllium in heated ruby-sapphire
  • Learn the latest treatment of the lead-filled rubies, pink sapphires and examine different types of rubies before/after the treatment
  • Be informed on the re-crystallization process of blue sapphires and the heating procedures involved
  • Recognize the integrity of the heat-treated ruby-sapphire and maintain consumer confidence with proper detection and disclosure
  • Find out how to calculate cost effectiveness ratio and yields before/after the heating process
  • Learn how to read a "Gemstone Report" (or "Gem Cert") and understand its real role in the industry
  • Be informed on the past and latest prices on rubies-sapphires sold in Thailand and in the USA
           SITE MAP


Site Updated Dec. 18, 2014
Best viewed with Firefox/Chrome at 1280 pixels

Copyright © Ted Themelis 2015