FEATURES
This course is intense and interactive covering most issues in gem treatments. During the training course and at the most appropriate occasion the following will be presented and performed by the participants:
A) Presentations & Demonstrations
- About 45 PowerPoint presentations that convey the principals, definitions and fundamentals in gem treating technology
- Four video clips will be shown as performed in India, Sri-Lanka and Thailand: "Romancing the Geuda" (1985), "Dyeing Chalcedony" (2002), "Oiling Emeralds - the Jobin process" (2005), "Heating Quartz" (2005)
- The most sought heating processes of blue sapphire will be demonstrated as performed in Sri-Lanka and elsewhere using the LAKMINI furnace.
- Heat processing equipment-parts, instruments, heating elements, ceramics, fluxes-chemicals and related materials will be provided for demonstration purposes (not to be taken out of the class)
B) Lab sessions (Practical examinations of gemstones)
During the presentations hundreds of untreated-treated gems will be examined. Each participant is assigned to a work station equipped with a gemological microscope.
C) Lab sessions (Hands-on experience on gem treatment)
Participants will prepare suitable samples and perform four treatment processes:
- PROCESS #1 (HEAT). Heating selected rubies and pink sapphires from Vietnam, Madagascar, Tanzania, etc. Prepare and execute a heating process using gas fugacity with/without fluxes.
- PROCESS #2 (HEAT): Heating select, rubies & sapphires from Songea, Madagascar, Tunduru, etc. Prepare and execute a "dry" beryllium heating process using a high-temperature electric furnace.
- PROCESS #3 (HEAT): Heating quartz, beryl, tourmaline and other gems as performed in India, Brazil and elsewhere using a low temperature furnace.
- PROCESS #4 (FRACTURE FILLING): Perform the oiling process of emeralds as performed in India, Colombia and Brazil.
Gem treatment equipment used in the practical sessions:
- A vertical muffle 1800oC electric furnace will be available for heat-treating ruby-sapphire (process #1 and #2)
- A low-temperature (1200oC) will be available for heat-treating quartz (process #3)
- High pressure oil-filling apparatus will be available for treating beryl
- Selected gems, additives and ceramics needed for the practical process will be supplied.
- Suitable gems can be brought by the students for treating if the gems are compatible with the target sought using process #1, #2, #3, #4 and #5
Part I. OVERVIEW: INTRODUCTION & CONCEPTS. (PowerPoint presentations; demonstration of various apparatuses; microscopic examination of untreated-treated gems)
- Understand corundum as an imperfect crystal
- Fundamentals of heat and the effect of heat in gems
- Comprehend temperature measurement (types, description, calibration)
- Learn the fundamentals and concept of oxidizing-reducing atmosphere, buffering & non-buffering reactions, gas fugacity, and influence of gas fugacity in heating gems
- Master the muffle concept and how to obtain precise gas mixtures
- Understand gas technology and gas mixing
- Learn the concept of diffusion phenomenology
- Overview on additives and fluxes
- Be familiar and work with different types of ceramics used in gem treating processes
- Understand the various types of various gem treatment equipment
- Learn about the various gem treating processes and equipment are practiced in the market: Heating, Filling, Laser Drilling, Irradiation, High-Pressure-High Temperature (HPHT), Impregnation, Bleaching, Bonding, and Coating
Part II. HEAT TREATMENT OF RUBY-SAPPHIRE (Powerpoint presentations; microscopic examination of selected gems before-after treatment; demonstration of various apparatuses)
- Review the historical aspects in heating ruby-sapphire
- Recognize the various treatment types of ruby-sapphire
- Plan the strategy in heating ruby-sapphire
- Learn about additives and fluxes: methodology, application, safety & handling. Learn 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 used in heating ruby-sapphire, i.e. traditional kilns (coke, lignite), diesel-oxy furnaces, LPG-OXY, etc.
- Watch a very rare documentary videotape in heating geuda sapphires using a traditional LPG-oxy furnace filmed by Ted in 1985.
- 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 beryllium-treated 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 related technology of 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.
Part III. TREATMENT OF SELECTED GEMSTONES (Powerpoint presentations on the treatments practiced; microscopic examination of the gems before-after treatment):
Apatite, Beryl (emerald and green beryl, aquamarine, heliodor, morganite, red beryl), Chrysoberyl, Diamond, Feldspars (moonstone, amazonite, andesine), Quartz (rutilated, rock crystal, amethyst, citrine, ametrine, rose, chalcedony), Jade, Kunzite and green spodumene, Lapis-lazuli, Malachite, Opal, Peridot, Rhodochrosite, Rhodonite, Ruby and Sapphire, Scapolite, Sodalite, Tanzanite, Topaz, Tourmaline (rubellite, indicolite, elbite), Turqouise, Zircon.
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