The Encyclopedia · Stones & materials
Synthetic gemstone
A stone made in a laboratory with the same composition and structure as its natural counterpart.
Synthetic rubies have been made by flame fusion since the early 1900s, followed by synthetic sapphires and spinels. In the Art Deco period they were sometimes used deliberately in fine jewels, as calibré stones or for colour. A synthetic is not an imitation, but it is worth far less than a natural stone and should always be disclosed.
What to look for
Under magnification, flame-fusion synthetics often show curved growth lines and gas bubbles. A laboratory can confirm.
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