In the foreground on the left, a spall mark is visible, providing a piece of evidence that this stone was heated. Although it looks like a small water droplet, it is “frozen” in place and cannot be rubbed or scraped off. In the background, we also see a shiny melted crystal “discoid,” confirming that the stone is heated.
Natural Sapphire • Sri Lanka (Ceylon) • Enhancements: Heat (H) • Lighting Conditions: Fiber Optic: Diffuse Overhead
Photographer: E. Billie Hughes •
Image Number: A-001-5147-1 • Date Posted: 18 March 2016
Hughes, R.W., Manorotkul, W. et al. (2017) Ruby & Sapphire: A Gemologist's Guide. Bangkok, Lotus Publishing, 816 pp.; RWHL*.