This partially healed fissure in a fingerprint pattern consisting of interconnected tubes is a rare occurrence in natural spinel, and confirms that this Sri Lankan cobalt-blue spinel is natural. The form taken by the tubes reveals the isometric symmetry of the underlying spinel. In long-wave UV, this stone displayed a strong green glow, something that is also found in cobalt spinels from Vietnam.
Natural Spinel • Sri Lanka (Ceylon) • Enhancements: None Detected (None) • Lighting Conditions: Dark Field
Photographer: Richard W. Hughes •
Image Number: A-003-4768-1 • Date Posted: 02 October 2019
Gübelin, E.J. and Koivula, J.I. (2005) Photoatlas of Inclusions in Gemstones, Volume 2. Basel, Switzerland, Opinio Publishers, 830 pp.; RWHL*.
Hughes, E.B., Koivula, J.I., Manorotkul, W., Renfro, N. and Hughes, R.W. (2019) Spinel inclusions: An exercise in aesthetics. InColor, No. 43, pp. 48–55; RWHL*.