Solids Doublets Triplets

What is a solid opal? What is a doublet opal? What is a triplet opal? Are boulder opals solid opals? What is a traditional finish? What is a polytop finish?

Solid Opal

A solid opal is a natural gemstone that has been cut and polished to expose the color and prepare the opal gemstone for setting. Nothing is added and the gemstone is all natural.

A solid polished opal can be worn in water and is the best form of opal for investment.



A solid boulder opal

Doublet Opal

A doublet is a man-made composite opal gemstone. Doublets are thin slices of opal that have been glued onto a backing. Doublets can be identified at the join where the opal and backing meet.

If the join is regular (like a straight line) it is a doublet. If the join is irregular (uneven/erratic) the gemstone is solid.

Opal doublets should be worn with care are they tend to be weak on the edges.

Opal doublets should not be worn in water.

Opal doublets are used in gemstone fashion jewelry although good quality doublets have real investment value.

FAQ: Boulder opals have a rock backing are they solid opals?

Boulder opal is naturally backed by rock and the junction where the rock and opal meet is irregular with many natural inclusions. The irregularity of the join indicates a natural bond between rock and opal which means the opal gemstone is a solid opal.


A doublet opal


Opal Triplet


 A triplet opal gemstone


A triplet opal is a very thin slice of opal that has been glued to a backing and protected by a clear quartz (or plastic) cap. Price is usually the give away with triplets. Triplets are generally really bright and quite inexpensive. Triplets are often used in fashion/souvenir jewelry.

Triplets should not be worn in water as water can get in under the quartz cap and cause ‘clouding.’

Opal finish

Traditional finish:

The traditional method of cutting and polishing opal requires the opal gemstone to be ‘faced’ down to expose the opal color.

Facing down refers to the process of removing the rock or common opal from around the band of opal color. Learn more about cutting boulder opal here

This is done using fine saws and diamond grinders in water. Water keeps the opal cool. If an opal gets too hot it will crack.

Once the opal has been prepared it is polished with a paste to remove all the scratches.

The polished opal is then turned over and the back of the gemstone is finished in the same way.

This is the traditional way of finishing opal. Facing down, grinding, sanding and polishing.

Sometimes this process can reduce the scenic value of the opal gemstone in which case a polytop finish is available.


 A solid boulder opal with a traditional finish

Polytop Finish:


A solid boulder opal with a polytop finish


A polytop finish is achieved when a polymer seal is added to the face of the gemstone to protect the image and promote longevity. The opal gemstone is still regarded as a solid opal in that it has been prepared in the traditional way using saws and grinders but if the opal is thin (as can happen with Boulder Opal) or the image contains many inclusions (such as cracks and pits) the polytop is used to seal the opal and conserve the image.

We choose to use the polytop finish for the Opal Art Scenic Range. Learn more about the Scenic Range here