Synthetic gemstones are really a 20th century invention. Synthetic gemstones are defined as man made gemstones which possess the same properties as natural gemstones. They are not the same as imitation gems which are things like paste stones or a white topaz being used to imitate a diamond, or plastic masquerading as tortoiseshell. Synthetic gemstones are identical to the natural stone, with the same appearance, chemical composition and physical characteristics but they have been created in a laboratory. Even cultured pearls cannot be considered to be synthetic gems as they are grown within the oyster or mussel host.
Early attempts to create gemstones in a laboratory started in France around the 1830s and the first synthetic ruby was produced in 1877, but it was not until 1904 with the publication by Auguste Verneuil of his processes and his patenting of the Verneuil furnace in France that it became possible to produce a synthetic rubies in commercial quantities. This doesn’t mean that synthetic rubies suddenly flooded the market but their use in jewellery can be dated from after this period.
Synthetic spinels were first produced using the Verneuil method in 1908 and sapphires in 1910. A new process for creating synthetic gemstones, the Czochralski pulled growth method, was patented in 1915, and was mainly used to produce crystals for semi-conductor use. However, it was also found to produce synthetic rubies, sapphires, spinels, alexandrite, chrysoberyl and garnets.
Emeralds proved to be a challenge to create and it was not until 1928 that the first synthetic emeralds were created using what is called a hydrothermal process. The stones were small, however, but in 1935, a commercial sized emerald was created by IG Farbenindustrie in Germany using the flux fusion process, followed in 1935 by Charles Chatham in the US. In the 1960s, Pierre Gilson from France began commercially producing emeralds (Gilson went on to create synthetic opals in the 1970s). Tairus emeralds were also created in Russia around this time using the hydrothermal process. A synthetic emerald known as the Biron emerald is created now in Western Australia.
Synthetic diamonds have been the hardest gemstones to create synthetically. Because of this, a number of imitation diamonds were created to fill the gap. One such imitant is cubic zirconia, which has no natural gem equivalent, and was first sold commercially around 1977. Since the late 1990s, synthetic diamonds are now being created, using a couple of processes, including high-pressure high-temperature processes.
So synthetic gemstones only began to be used in jewellery after the first world war and can be found in Art Deco jewellery. Rubies, sapphires and spinels are the main stones used. In some instances, lost stones in antique jewellery may have been replaced by modern jewellers using synthetic gems. Purchasers should be advised if stones in jewellery are lab created stones.
Next week: antique paste jewellery.