Micro-World Gems & Gemology, Spring 2019, Vol. 55, No. 1

Lazurite in Spinel

Blue lazurite in a light gray spinel.
This light gray spinel from Mogok, Myanmar, contains a vibrant blue inclusion of lazurite. Photomicrograph by Nathan Renfro; field of view 1.59 mm. Courtesy of Mark Smith, Thai Lanka Trading Ltd.

Spinel is often inclusion free but occasionally showcases unusual inclusions. This was the case with a 1.02 ct light gray Burmese spinel from Mogok, courtesy of Mark Smith (Thai Lanka Trading Ltd., Bangkok), that was recently examined by the authors. A striking vibrant blue inclusion reached the surface of the pavilion, making Raman analysis straightforward (see above). The identity of the blue inclusion was confirmed to be lazurite. The mineral has previously been found as an inclusion in Burmese ruby (Spring 2012 Lab Notes, pp. 51–52), but this is the first instance of a lazurite inclusion in spinel that we are aware of.

Nathan Renfro is manager of colored stones identification, and John I. Koivula is analytical microscopist, at GIA in Carlsbad, California.