Why are rubies heated? Following high temperatures, what changes occur in their colour, clarity, and internal world? Presented by Dr Fan Cheng, who has dedicated over a decade to ruby research and identification, this seminar offers a glimpse into the true world of ruby heat treatment. From actual heating procedures and before-and-after transformations to the subtle clues revealed through microscopes and scientific equipment, discover the science behind a ruby’s “thermal transformation” step-by-step. Go beyond appreciating rubies to understanding them through a professional gemmological lens.
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Step2: Registering for this seminar
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Ruby’s Thermal Transformation: Unveiling the Scientific Secrets of Heat Treatment
• Date/Time: 22nd November 2026, 11:30-12:30
• Venue: Taiwan Jewellery & Gem Fair | Stage Seminar Area
• Speaker: Dr Fan Cheng
• The organizer reserves the right to change/modify/suspend/cancel the event.
What happens when a ruby is placed inside a high-temperature furnace?
In the jewellery market, heat treatment is one of the most common and vital processes applied to rubies. However, heating is far more than simply roasting a gem—variations in temperature, duration, and atmospheric conditions can dramatically alter the stone’s final appearance.
Led by Dr Fan Cheng, this seminar draws on authentic research and identification case studies to explore the technology and science driving ruby heat treatment.
What you will explore in this seminar:
✦ Why are rubies heated? Understand how high-temperature treatment impacts a ruby’s colour, transparency, inclusions, and fractures.
✦ How are rubies actually heated? From temperature and timing to environmental atmospheres, learn about genuine gemstone thermal processing operations and key conditions.
✦ Can you really tell if a ruby has been heated? From visual observation and microscopy to spectroscopy and chemical analysis, see how gemmologists uncover the evidence left behind by heat.
From the furnace to the microscope—this session goes beyond admiring the beauty of a ruby to understanding exactly how that beauty comes to be.
Speaker Profile
Dr Fan Cheng
MD minerals and Gem research
With over ten years devoted to ruby research and identification, Dr Fan Cheng specializes in the gemmology, heat treatment, and testing practices of rubies and sapphires, having personally conducted extensive experimental studies in the field. Possessing a wealth of practical experience in specimen observation and analytical research, he is committed to integrating scientific inquiry with professional testing practice to explore the origin, features, treatment, and identification of rubies.