Synthetic and Simulant

Synthetic and simulant are terminology used by the USBM for laboratory grown gemstones. Others in the gemstones industry may use different terms to refer to laboratory grown gemstones. Laboratory grown synthetic gemstones have essentially the same appearance and optical, physical, and chemical properties as the natural material that they represent. Synthetic gemstones produced in the United States include alexandrite, coral, diamond, emerald, garnet, lapis lazuli, quartz, ruby, sapphire, spinel, and turquoise. Laboratory grown simulants have an appearance similar to that of a natural gemstone but have different optical, physical, and chemical properties. The gemstone simulants produced in the United States include coral, cubic zirconia, lapis lazuli, malachite, and turquoise. Additionally, certain colors of synthetic sapphire and spinel, used to represent other gemstones, would be classed as simulants. Colored and colorless varieties of cubic zirconia are the major simulants produced.

In the past few years, the use and consumer acceptance of synthetic and simulant gemstones have grown. Much of this growth is the direct result of the recognition of these gemstones for their own merits, not just as inexpensive substitutes for natural gemstones. In 1993, the reported value of production of U.S. synthetic and simulant materials was $17.9 million, about a 5% decrease from that of 1992, according to the USBM. Since the USBM began collecting data on the value of production of synthetic and simulant gemstones in 1986, the U.S. production has averaged about $17.0 million per year, with a low of $10.3 million in 1986 and a high of $20.5 million in 1990. During the past 5 years, the annual value of production has averaged $18.8 million with annual increases or decreases from 5% to 13%.

Synthetic ruby.
(Photo is courtesy of J.O. Crystals.)

Synthetic and simulant gemstone producers use many different production methods, but they can be grouped into one of three types of processes: melt growth, solution growth, or extremely high-temperature, high-pressure growth.