First and foremost, don't be turned off by the word synthetic. "Synthetic" may sound like a synonym for fake, but it's actually not that simple.
Synthetic opals are synthesized in a lab, but they aren't necessarily "fake." This is an important distinction; while synthetic opal is man-made, it has chemical and physical properties that are identical to a genuine opal found in nature. Most importantly - synthetic opals still have the "play-of-color" qualities that make genuine opals so desirable.
You might also come across an imitation opal, which is a completely different material. Imitation opals are often simply glass or resin paired with tiny flecks of foil or another eye-catching material. They are still very beautiful, but are not technically opals.
The best thing about synthetic opals? They are just as beautiful as precious opals, but are very affordable.
How to identify a synthetic opal:
- Do the opal's fiery features look uniform? Do the flecks in the opal appear square-ish in shape and consistent throughout the entire stone? As a general rule of thumb, synthetic opals have a much more uniform structure than natural opals, resulting in a pleasing, almost tessellating pattern.
- Do you notice long columns of color when you look at the opal from the side? This is another sign of its uniformity, indicating it's a synthetic opal.
- Is the opal streaked with cracked, black lines? These are called "inclusion lines" and are yet another indication of a synthetic opal.
- Is the back of the opal sandy in texture? This is a strong indication that the opal is natural.