Feature Gems & Gemology, Fall 1987, Vol. 23, No. 3

The Lennix Synthetic Emerald

The Lennix synthetic emerald, currently manufactured in France, is a dark green, moderately transparent to translucent material grown by flux fusion. With the microscope, zones of lighter and darker green are evident. For the most part, the gemological properties of this synthetic emerald overlap those of natural emeralds, although the low refractive-index and specific-gravity values are good indicators that this material is synthetic. The presence of "wispy veil" inclusions provides conclusive proof of synthetic origin, as do the chemical analyses, infrared transmission spectra, and cathodoluminescence.