BY CRAIG THOMAS
The term “synthetic” has been very controversial lately so let us explore the definition so that we may better understand the meaning behind this word.
Firstly let’s define the word artificial. Artificial means made or produced by human beings rather than occurring naturally. Artificial is a broad term used to describe both synthetic and manmade imitation gems.
Left to right: Synthetic Moissanite, Synthetic Cubic Zirconia, Natural Zircon.
The standard definition for synthetic is very similar to that of artificial, made by chemical synthesis, especially to imitate a natural product. In gemmology however the gemstone must meet specific criteria in order for it to be called a synthetic. An artificial gemstone that has a natural counterpart with the same composition, structure, optical and physical properties may be termed a synthetic.
So in order to be called a synthetic a manmade gemstone must have a natural counterpart that is identical in every way, except the manner in which it was formed.
Left to Right: Natural Sapphire, Synthetic Sapphire, Glass (manmade)
Then what is a simulant? A simulant is defined as a thing which simulates or resembles something else. In gemmology this is interpreted as a natural or artificial material that is used to imitate the effect, colour and appearance of another gem material without possessing
its chemical composition and physical properties.
Left to right: Natural Garnet & Glass (manmade) Doublet, Glass (manmade), Synthetic Ruby, Natural Ruby
If we look at diamond for an example, natural diamond is formed in the earth’s mantle. However there are “synthetic” diamonds that have the same chemical composition and physical properties as the natural stone but they were formed at the earth’s surface with the help of manmade processes.
Left to Right: Natural Emerald, Synthetic Emerald, Natural Mtorolite Chalcedony, Glass (Manmade)
Then there are also natural gem materials that have been used by man to imitate a diamond (diamond simulants), for example, white zircon, colourless sapphire and silver topaz. There are also many artificial gems that have been employed as diamond simulants, such as synthetic cubic zirconia, synthetic moissanite, strontium titanate, glass and many others. What is interesting to note is that many of the diamond “simulants” are also synthetics in that they have natural counterparts with the same chemical composition and physical properties. However these synthetics are being produced to imitate diamonds and that is why they are referred to as simulants, they should never be called synthetic diamond as they do not possess the same chemistry and physical properties as a diamond.
I hope that this clarifies the difference between a synthetic and a simulant for those that were unsure.
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