Sterling Opal

This beautiful pendant by Thomas Francisco is made with a piece of Sterling Opal.

Sterling Opal Pendant by Thomas Francisco


The information below is from the manufacturer’s website Sterling Opal

“Sterling Opal has created a new lab-cultured  gemstone that combines the play of color and distinctiveness of genuine opal with the economic pricing of synthetic opal.

Over twenty years ago Jim Zachery, the developer of the Zachery Process for turquoise set out to develop a lab cultured opal.  He tried to purchase silica from major manufacturers but found that none of them produced a silica product with the uniformity necessary to create quality opal.  He had to take a step back and change his priorities from creating the perfect opal to creating the perfect silica.

It took him many years but he eventually developed a process to produce silica nano and micro spheres in commercial quantities with a polydispersity of .005 or better. This gave him the building blocks to begin development of a lab-grown opal. Nature’s ability to produce silica with the uniformity necessary to create opal is miraculous. It is only slightly less remarkable that man can achieve a very similar outcome in a laboratory.

About Our Cultured Opal
Until now, the only lab created opal available had very consistent domains and color. Most of this consistency in color is maintained by using dyes.  While many colors are available in other synthetic opal because the color is produced by dye, each piece of opal only contains one color and not much “play of color” if any.  In other words, the color doesn’t change or move with different angles of light.  Sterling Opal will not use dye in their products; all color in Sterling Opal is the result of Bragg diffraction of visible light as occurs in natural opal.  Furthermore, because their processes mimic nature, most pieces of opal have a diversity of color and depending on the angle of the light the opal will change color.
The beauty of Sterling Opal is that while they are able to settle large batches of opal that will all have a similar look, each piece of opal is still quite unique.  The opal is grown mainly in 1½” x 2½” squares, in lots of approximately 4.5 kilos.  This enables jewelry manufacturers and designers to create many pieces of jewelry that have a similar look yet each piece will be unique.  It is the unique look and the brilliant play of color that sets Sterling Opal apart from any other lab grown opal manufacturer.

Sterling Opal is currently created in several distinct designs and color waves.  Each of these styles is created using a different proprietary process.  While all of the varieties have dazzling color they each have a distinct appearance.  The designers at Sterling Opal continue to work on new processes that will result in original creations to rival natural opal in its color and individuality.  The unique qualities of each stone in its variety of forms will enable jewelry designers to conceive unique jewelry pieces with brilliant opal at a fraction of the price of genuine opal.”

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Native American Jewerly Materials – Opal

Hi Paula,

I think the opals used on bracelets are mostly (very pretty) Gilson opals. Am I right? I have a Thomas Francisco designed bracelet, and although nothing says synthetic, I think they must be, they really look like the Gilson opal pictures.


Opal Inlay Bracelet by Thomas Francisco, Navajo

Hi Susan,

Great question and a good topic. First of all, we’ve never seen Native American pieces that use natural or precious opal. As you will read below, part of the reason is the scarcity and availability of precious opal.

But the other factor is that when used in inlays or other settings, natural opal has a higher tendency to crack than lab or imitation opal. So when we purchase items with opal in them and ask the artists about the materials, about the opal, they reply “lab opal” but most opal used in Native American jewelry is actually imitation opal.


Opal has a latticework of spheres and spaces that play with light as it passes through  – something like a prism.

Light passes through the arrangement, speeding up and slowing down as the size of the spheres and spaces between them changes and as the the angle of view changes.

The longer light waves produce RED-PINK color hues.

Imitation Pink Opal

Imitation Pink Opal

The shorter waves produce the BLUE-GREEN color hues.

Imitation Blue Opal Bracelet by Thomas Francisco, Navajo

Imitation Blue Opal Bracelet by Thomas Francisco, Navajo

So when you wear your opal jewelry indoors under various types of lights and outdoors under different light settings, you will see a change in the stones. Photographing opal to show its great variety is indeed a challenge !

Natural opal (also known as precious opal) contains between 3-10% water but can be as high as 20%

For technical information about natural opal.

More about Australian Opals.

Lab opal is considered a true synthetic or created opal – produced in controlled laboratory conditions and with the same chemical composition as natural opal but with a very low moisture content.

opa butterfly

Zuni Imitation Opal Butterfly Pin Pendant by Earline Edaackie

Some lab opals are more expensive to produce than the natural stone would cost. Lab opal is very resistant to breaking due to the fact it does not contain as much water as natural opal.

Multi-Color Opal Corn Row Watch by Thomas Francisco, Navajo

Multi-Color Imitation Opal Corn Row Watch by Thomas Francisco, Navajo

Gilson opal is the premier lab opal, the choice of many Native American artists.

Gilson opal production began in 1974 by Pierre Gilson when he discovered the ordered sphere structure that gives precious opal its light reflecting abilities. Laboratory production of opal is a highly complex process that can take over a year to complete. The colors are natural without color enhancement.

Imitation opal AKA artificial or simulated opal is different chemically from natural or lab opal. It is made up of 80% silica and 20% resin and is an economical option to both precious and lab opal.

Even when opal is not used as the main stone, but as an accent such as in this link bracelet, it brings a whole new dazzle to the piece.

Rhodochrosite, Opal and Mother of Pearl Inlay Braclet by Shirley Tso, Navajo

Rhodochrosite, Imitation Opal and Mother of Pearl Inlay Braclet by Shirley Tso, Navajo