platinum ring with blue zircon in bezel settingplatinum ring with blue zircon in bezel setting

Zircon Heat Treatment

Are zircons natural gemstones? Learn how zircon heat treatment works and the difference between zircon and cubic zirconia.

6 Minute Read

HomeLearning CenterZircon Heat Treatment
faceted zircons in various colors
Zircon color suite. Photo © Joel E. Arem, PhD, FGA. Used with permission.

What’s the Difference Between a Treated Gem and a Lab-Created Gem?

Gem buyers may want to know if their prospective purchases have been treated and whether they are mined or lab-created. Vendors should be able to answer their questions. Let’s clarify the difference between treatments and synthetics.


Treatments or enhancements are processes that change the properties of a gem, such as altering its color or clarity. For example, a naturally blue-green aquamarine may be heated to change its color to pure blue. An emerald may receive fillers to improve its clarity.

pink zircon - zircon heat treatment
Heating improved the color of this light pink zircon. Round brilliant cut, 1.21 cts, 5.47 mm, Tanzania. © Rob Lavinsky, Used with permission.

Cutting and polishing are not considered gemstone treatments. These procedures may make a stone more aesthetically pleasing but don’t alter its properties.

Lab-Created Gems

Synthetic or lab-created gems have the same optical and physical properties as their natural counterparts. Only their origins differ. While natural gems may form underground, synthetic gems grow in controlled laboratory conditions. For example, synthetic diamonds have the same properties as

Emily Frontiere

Emily Frontiere is a GIA Graduate Gemologist. She is particularly experienced working with estate/antique jewelry.

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