GIA Spots Synthetic Ruby with Natural Appearance

The Gemological Institute of America (GIA) recently examined a Ramaura synthetic ruby with angular milky cloud inclusions that presented as natural.  

A customer submitted the 2.14-carat gem, which was mounted in a ring, to the GIA’s Tokyo laboratory for identification and an origin report, the organization said in its most recent issue of Gems & Gemology, published last week. The ruby also showed unusual wispy veil-like milky clouds, strong angular graining and triangular negative crystals containing flux-like materials and minute bubbles.  

While the milky clouds are generally representative of a natural stone, the other characteristics are associated with flux-grown synthetic rubies, the institute explained.  

The GIA determined the stone’s true chemical nature using laser ablation-inductively coupled plasma-mass spectrometry. The analysis revealed lower concentrations of magnesium and gallium and much higher concentrations of lanthanum, platinum and lead than those found in natural rubies. Those features, as well as the absence of vanadium, were abnormal for a natural ruby and instead suggested a Ramaura flux-grown synthetic ruby, meaning it was grown using a proprietary process in a hot liquid, called flux. However, there had not previously been a report of a synthetic ruby bearing natural-looking milky inclusions.   

“Surprisingly, such milky clouds and flux inclusions could be confused with heated natural ruby and might cause misidentification,” the GIA said. “Careful observation of inclusions in the stone and chemical analysis were both needed to confirm that this was a laboratory-grown ruby.”

Image: A close-up of the milky clouds in the synthetic ruby. (Gemological Institute of America)