Further evidence is found by carefully examining the mixed crystal exsolved rutile silk. Such inclusions typically unmix into two different solid phases, one highly reflective and the other of lower relief. When such crystals are heated, the lower relief crystals may begin to break down, developing irregular white patches, as one can see here, particularly in the crystal at the center left of the field of view.
Natural Ruby • Mozambique • Enhancements: Heat (H) • Lighting Conditions: Fiber Optic: Oblique
Photographer: Richard W. Hughes •
Image Number: A-004-1219-3 • Field of View = 1 mm • Date Posted: 04 February 2022
Pardieu, V., Saeseaw, S. et al. (2015) "Low temperature" heat treatment of Mozambique ruby: Results report. Gemological Institute of America, 16 April, 34 pp.; RWHL*.