When Burmese rubies, such as this stone from Mong Hsu, are heat treated, they often develop a zoned chalky fluorescence in shortwave UV. In this position, the stone’s original blue core has been removed by the heat treatment, but that zone does not display the chalky fluorescence, just fluorescing red.
Natural Ruby • Myanmar (Burma); Mong Hsu • Enhancements: Heat + Fissure Healing (H-FH) • Lighting Conditions: Ultraviolet: Shortwave
Photographer: Patharaphum Sudprasert •
Image Number: A-001-4392-2 • Date Posted: 25 January 2016
Hughes, R.W. and Emmett, J.L. (2005) Heat Seeker: UV fluorescence as a gemological tool. The Guide, Vol. 24, No. 5, Part 1, Sept.–Oct., pp. 1, 4–7; RWHL*.