Drippy, melty fingerprints are a hallmark of flux heated corundum.
Natural Ruby • Not Determinable • Enhancements: Heat + Fissure Healing (H-FH) • Lighting Conditions: Dark Field
Photographer: E. Billie Hughes •
Image Number: A-002-8614-1 • Date Posted: 26 March 2018
Hughes, R.W., Manorotkul, W. et al. (2017) Ruby & Sapphire: A Gemologist's Guide. Bangkok, Lotus Publishing, 816 pp.; RWHL*.
Emmett, J.L. (1999) Fluxes and the heat treatment of ruby and sapphire. Gems & Gemology, Vol. 35, No. 3, Fall, pp. 90–92; RWHL*.