First successful attempt to production of synthesized Beryl occurred in San Francisco around 1940 by in.
Carroll Chatham beat on time the scientist LG. Farben (that claimed first success in synthesis of emerald five years before), with a first production of synthesized Emerald crystals.
Chatham’s synthetic emeralds looked like natural emeralds, far better than the lab gemstones produced through the so called Verneuil process with the typical gas bubbles and curved stripe. Chatham’s synthetic emeralds contain veils of solid flux inclusions and occasionally neutral phenakite crystals and grey platinum crystals. Chatham synthetic emeralds present a noticeable secondary hue not always present in natural emeralds.
Although the early product was, very limited in size, large crystals-over 1000 carats have been made by Chatham was able to produce huge crystals over 1000 carats, however the main production focused around medium size stoned.
Many years after, Gilson started to produce flux-melt synthetic emerald, that looked very similar to fine natural emerald. First Gilson’s gemstones presented a noticeable orange fluorescence under longwave ultraviolet light, then removed by adding iron oxide. In 1961, we see the “Linde Synthetic Emerald” appearing on the market. It was a pre-faceted natural beryl coated with a layer of hydrothermal synthetic emerald but met a little success, since it was easily detectable- Few years later the Linde Company, introduced a hydrothermal synthetic emerald, that revealed excessively fluorescent, and did not have success. not commercially successful. Hydrothermal synthetic emeralds are now produced by Regency Emeralds and show properties much closer to natural emeralds, but reveal the presence of conical cavities (called nail head spicules) originating from phenakite crystal inclusions and aa cottony appearance, especially near the interface between seed and new growth, when a seed is present. Minute two-phase inclusions often present in parallel lines, and layers can be visible at right angles, with concentrations of colour highlighting growth stages from the seed plate outward. The arrangement and nature of inclusions diverge distinctly from flux-melt emeralds.