Crushed Opal – Production, Properties, and Uses

Production, Properties and Use of Crushed Opal

Opal Shards, Dust and Powder

What is Crushed Opal?

As the name suggests, crushed opal is simply opal that has been broken down into smaller pieces.
However, both terms – “crushed” and “opal” – cover a fairly wide spectrum of particle sizes and material types.

The term “crushed” refers to a specific range of particle sizes, spanning from powder to fine, medium, and large.
While exact millimeter measurements vary by supplier, large is typically 2 mm and above, medium covers roughly 1 to 2 mm, and fine ranges from 0.5 to 1 mm.

The term “opal” in crushed opal can refer to vastly different material types - whether natural, synthetic, or imitation - and should always be clarified before use.
While the vast majority of crushed opal products on the market consist of polymer-impregnated synthetic opals, natural opals are also processed and offered as crushed opal.
Furthermore, there are synthetic Gilson opals and Gilson-like opals, which, according to CIBJO definitions, are the only materials strictly considered true synthetic opals.
Polymer-impregnated synthetic opals are actually classified as opal imitations, a category that also includes Aurora Opals and the coarse-crystalline opal type.
However, these latter types of opal imitations cannot be processed into crushed opal due to their high polymer content, as the material is far too tough.

Making crushed opal with mortar and pestle

Making crushed opal with a threaded fitting

Making crushed opal with a threaded pipe double nipple

How Crushed Opal is Made

Synthetic Opal Manufacture

With minimal effort, rough opal is first cut into small pieces, crushed by hand using a mortar and pestle, and then separated into different particle sizes using sieves.

To prevent opal chips and shards from flying around, a method adapted from turquoise processing works best. Using a standard pipe nipple and end caps from a hardware store allows you to crush small batches of opal safely with minimal waste.

For a more professional approach with reproducible results, a jaw crusher is essential. Companies like Retsch or Fritsch specialize in developing and distributing these types of machines, which can crush materials ranging from 6 mm down to fine powder depending on the model.

Regardless of the method used, the crushed opal chips must be washed after processing to remove any remaining dust. Only then is the crushed opal ready for use.

Uses of Crushed Opal

Crushed opal made from polymer-impregnated synthetic opal is used in a wide variety of applications, including inlays for jewelry and woodwork, nail art, and the decoration of furniture and musical instruments.
In all of these uses, the opal chips must be dispersed and secured within a suitable medium - typically by embedding them in casting resin, adhesive, or nail polish.

Because resin-free synthetic Gilson opal and Gilson-like opal are significantly more expensive to manufacture, crushed opal of this type is almost exclusively used by glassblowers, glassmakers, and glass artists due to its exceptional thermal stability.
With a Coefficient of Expansion (COE) of 30.5 to 33, this opal is compatible with borosilicate glass and is incorporated into glass tubing, rods, spheres, marbles, rings, pendants, figurines, and other glass creations.

Crushed opal made from natural opal is also used for "floating opals." In this application, opal chips are suspended in a liquid medium - frequently glycerin - and sealed inside glass to be worn as pendants. Australian and Ethiopian opals are particularly popular for this purpose.

Crushed Opal, Resin Free Created Turquoise Gilson-like Opal

Synthetic Crushed Opal - Gilson-like Opal

Synthetic Opal - Dried Colloidal Particles

Synthetic Crushed Opal - Gilson-like Crystal Opal

Pros and Cons of the Opal Types Used for Crushed Opal

The main advantages of crushed opal made from polymer-impregnated synthetic opal are its ready availability, the vast range of colors and sizes offered, and its consistent quality.
The primary drawback stems from its polymer content (typically 20–25%). Because of this resin content, crushed opal of this type is neither heat-resistant nor resistant to aging.

In contrast, Gilson opal and Gilson-like opals are purely inorganic, consisting solely of silica (silicon dioxide) and coloring agents. As a result, these synthetic opals have the advantage of being both high-temperature resistant and age-resistant - Gilson opal encased in glass is literally made to last forever.

However, the manufacturing process for these opals is significantly more complex, making the resulting crushed opal substantially more expensive.
Due to this high price, the use of this crushed opal type is almost entirely limited to glassblowers, lampworkers, glassmakers, and glass artists.

How Much Does Crushed Opal Cost? – Pricing

A price comparison of various Etsy listings for polymer-impregnated synthetic crushed opal revealed that the average price currently sits at €11.43 per gram (as of July 2026).
The maximum price was €13.29 per gram (across 4 sellers, marked in red), while the most affordable deal came in at €7.62 per gram (a single listing, marked in green).

For crushed Gilson opal, Etsy yielded only a single listing, priced at €10.00 per gram.

On various websites across the internet, crushed Gilson opal is generally offered at an average price of roughly €13 to €22 per gram, with only one listing found at €10.00 per gram.

Crushed Opal, Price Comparison