Design Idea 951B Pendant

by Barbara van Look, Marketing Content Development Group, Exclusively for Fire Mountain Gems and Beads®

Opal is an uncommon gemstone with an equally uncommon beauty and a sadly common fragility--leading it to be recreated in the laboratory as a stronger composite that withstands the stresses the natural opal cannot.


Gem grade opal is extremely rare; therefore, it is also extremely expensive. Other opal materials--stones without the colorful flash of colors--are called "common opal" and are far more easily available. This includes natural gemstones such as fire opal, Mexican opal, Peruvian opal, brandy opal and more.

Simulated Opals, Man-made

Man-made simulated opals are manufactured in two ways. Some, like our Gilson® opals are cut from opaline silica grown in a laboratory, taking over a year to grow and "come into their colors." This slow growth results in a similar structure and material balance as natural precious opals, but with increased durability and structural stability. Gilson opals contain approximately 70-75% silica (similar to natural opal) within a trade secret base of translucent plastic or resin.

Simulated opals do not contain water like natural opals do--making them less vulnerable to changes in temperature, humidity and heat. Gemologists and industry experts agree, since no simulated man-made opal contains water, none of this material can legitimately be called "synthetic." Instead, the industry advocates calling all manufactured opal materials "man-made simulated."

Black Mosaic Opal
  • Black mosaic opals are stacked in a sandwich of materials: a backing layer made of glass, plastic or a variety of low-cost black stone materials, a layer of Gilson created opal and topped by a layer of clear glass. The layers are bonded with a strong epoxy.

White Opal Cabochon
  • White opals are a solid piece of Gilson created opal, cut to size and shape.

Black Opal Cabochon
  • Black opals are a solid piece of Gilson created opal, cut to size and shape.


Manmade Opal (also called "Simulant Opal")

Fire Mountain’s other simulated opals are Kyocera Corp block material, created in block form from 80% silica base material and 20% epoxy for hardness. They are more cost effective, easier to cut, grind and shape than the more brittle natural gems and are highly resistant to temperature changes, as well as dry environments. These stimulants are frequently used in the largest pieces cut from opal, such as figurines, inlay pieces or Dione® large-hole beads.

Although these materials are stronger than natural opal, cutting them is still a challenge. Each bead and cabochon for sale is a survivor of the cutting, drilling and polishing process. The high levels of silica means a significant level of breakage during cutting and drilling, yet to lower the level of silica is to decrease their beauty.
Design Idea C944 Necklace and Earrings

Designing with Synthetic and Manmade Opal

These lab-created and manufactured forms of opal result in stronger beads and stones, opening up creative options for jewelry makers. No longer are designers restricted to low-impact necklaces and earrings (and maybe the occasional cocktail ring). Now large pieces of opal-like components and beads are appearing in designs, such as generously sized Dione large-hole beads. Stronger materials means bracelets, buttons, anklets and other areas of jewelry with higher risk of impact can now showcase the signature play of colors in the opal.

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