vintage opal glass ring - opal simulants
vintage opal glass ring - opal simulants

Opal Simulants: How to Spot Imitation Opal


How can you be sure that a piece of opal for sale is genuine? Learn about the major types of opal simulants and how to distinguish them from the real deal.

5 Minute Read

What are Opal Simulants?

Opal simulants are materials that simulate, or look like, opal. Unlike synthetic opal, opal simulants have different chemical and physical properties, making them easier to distinguish from mined opals if you have the right instruments.

Because many different materials can be used as opal simulants, it's often useful to measure the gem's specific gravity and refractive index. However, with enough experience, you'll be able to distinguish most simulants using only your eyes and a loupe.

Take a look at this video, where experts talk about opal synthetics, simulants, and treatments and show examples of each.

Video © Opal Auctions. Used with permission.

Is it Unethical to Sell Opal Simulants?

As long as merchants disclose that what they're selling are lookalikes, materials created or presented to imitate genuine opals, there is nothing unethical about selling opal simulants. Imitations can still make beautiful jewelry stones, and some may even have more wearability than actual opals. However, customers should be told the truth about what they're buying.

Lab-Made Opal Simulants

Most opal simulants are synthetic materials formed from a reflective material in a matrix of glass, plastic, or resin. Some can appear quite...


Addison Rice

A geologist, environmental engineer and Caltech graduate, Addison’s interest in the mesmerizing and beautiful results of earth’s geological processes began in her elementary school’s environmental club. When she isn’t writing about gems and minerals, Addison spends winters studying ancient climates in Iceland and summers hiking the Colorado Rockies.

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