The large, reflective fissure around this crystal, likely mica, provides evidence that this sapphire has been heated. Mica crystals are particularly sensitive to heat.
Natural Padparadscha Sapphire • Madagascar • Enhancements: Heat (H) • Lighting Conditions: Dark Field + Diffuse Fiber Optic
Photographer: E. Billie Hughes •
Image Number: A-004-1640-1 • Field of View = 3 mm • Date Posted: 10 March 2022
Hughes, R.W., Manorotkul, W. and Hughes, E.B. (2017) Ruby & Sapphire: A Gemologist's Guide. Bangkok, Lotus Publishing, 816 pp.; RWHL*.
Saeseaw, S., Khowpong, C. and Vertriest, W. (2020) Low-temperature heat treatment of pink sapphires from Ilakaka, Madagascar. Gems & Gemology, Vol. 56, No. 4, Winter, pp. 448–457; RWHL.