The Origins of Synthetic Gemstones April 27 2017
Synthetic gems are ones that have been forged in the confines of a laboratory yet share all of the physical, chemical and optical traits of their natural counterparts. The first gem crystal of faceting quality to be synthesized was in fact a ruby and their production since the late 1800s has largely been as a result of its industrial applications outside of the jewelry industry. Its production can be engineered to remove virtually all of the flaws present within its counterparts’ natural lattice structure. Coupled with the increasing ability to manufacture ‘to order’, these synthetic gems have come under fire recently for being easily confused with naturally occurring gemstones.
During the past two centuries, scientists have derived an assortment of methods to create gem crystals in the laboratory. A large proportion of them fall into two main categories: melt or solution processes. In the melt process, the chemical composition of the melt is the same as that of the resulting crystal whereas in the solution process, the melt is of a different chemical composition. High temperatures are used to dissolve a variety of constituents into the melt or solution and then it is gradually cooled as the crystal grows from a seed like structure.
The Verneuil process was the first successful commercially viable production method for producing synthetic gems using the melt process. It was developed in 1902 by the French scientist, Auguste Verneuil and it involves dropping powdered chemicals through a downward directed flame, where it melts and forms a crystal on a rotating pedestal. It has become the most inexpensive method of manufacturing synthetic crystals such as corundum and is widely used across industries. An example of the solution process is the hydrothermal growth method. It is the only known method of rowing synthetic quartz but is requires a large investment in equipment, skilled technicians and patience. The method dissolves a mixture of nutrients into a water solution and immerses it into a specialized container that mimics the intense heat and pressure present deep inside the outer core of the earth where natural gems form. Once cooled in a controlled manner, this solution precipitates crystals that are near identical to Mother Nature’s own creations.
Synthetic sapphire crystals have been utilized in a wide array of applications from shatter resistant windows in armored vehicles to insulating substrates in integrated circuits used in computers, telephones and satellite communication systems. One particular use, sapphire glass, has seen a lot of media exposure recently given its use in many Apple products including their smart watches. Its versatility as a material derives from its ability to be highly transparent across a wide optical range (from ultraviolet to infrared wavelengths) and being highly resistant to scratching and abrasion than standard glass.
Given that synthetic gem crystals can have a remarkable similarity to naturally occurring gemstones, strict regulations are set in place to control how they are marketed and sold. For example, the Federal Trade Commission in the U.S. mandates the description of synthetic gem crystals to leave no doubt that it is not produced naturally. Other regulatory agencies such as the International Colored Gemstone Association (ICA) and the World Jewellery Confederation (CIBJO) have issued strict procedures that disclose the synthetic gemstone’s origin throughout the distribution channel at the time of sale, from the manufacturer to the consumer. In the past few decades, fewer and fewer synthetic gems have been marketed which suggests that its repertoire is nearing its limit but nonetheless, a careful eye is placed to ensure a fair and honest trade at every point of sale.
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