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Opals that have been formed into doublets or triplets, despite being a prominent practice for centuries, have been often overlooked by jewellers. This has lead to a distinct misunderstanding regarding surrounding these forms of opal jewellery, irreversibly tarnishing the otherwise-helpful jewellery technique.

What Are Opal Doublets and Triplets?

Not everyone can afford tens of thousands of dollars for a pendant or ring. By taking a ‘slice’ of an Opal and laying this against a background of a darker opal (usually boulder opal or black opal) 'potch' (Opal without colour) we can provide a completely natural piece of Opal in all of its splendour and beauty and make it affordable! The facts are as follows: opal triplets are genuine, but not everyone who sells them may be. The issue with these practices is not the opal itself, but jewellers who may not advertise that the opal is a doublet or triplet. The reason this is so important to see is that, without proper knowledge, customers may buy an opal under false pretences, thinking that their purchase is a solid opal when it is actually a triplet or synthetic piece (fake opal). Fundamentally, this has negative impacts on the fostering of trust between customers and wholesalers, which is something that can not easily be repaired.

Opal triplets were discovered in the 1960’s because some natural opals are shell fossils, which means they can be incredibly beautiful, yet exceptionally thin. This is furthered by the fact that Opal forms inside Boulder Opal and Black Opal in thin cracks and crevices. This discovery of raw opal saw Opal miners (from the 1920s and onwards) place some black or boulder opal behind the thin piece of natural crystal Opal to help provide that backing or strength to allow it to be more easily set into jewellery. The quartz crystal cap was added in the 1960s when Opal experienced a boom time with Japanese customers.

However, the creation of such a technique allowed for some unscrupulous practices to form as a result. Around the 1960s and 1970s, some jewellers began to use plastic as a backing for their Triplet opal jewellery, ultimately resulting in the pieces ‘falling apart’ over time as the two different materials reacted and shifted at different paces, causing delamination (and leading to the myth that Opal turns white over time or can lose its colour).

If you are looking for an opal gem that has all of the characteristics of a top black opal, but at a price you can afford, then doublets and triplets are for you. A doublet is a thin layer of crystal opal with a layer of potch - black common opal, an amorphous mineraloid comprised of hydrated silicon dioxide, or ironstone - on the back which acts to bring out the colour of the opal.

Now this black potch has value only as a backing for an opal doublet, because to make quality opal doublets, that won’t delaminate, we need to use material with the same “co-efficient of expansion”. If we put plastic on the back of the opal (and sadly some unscrupulous people do) to make an opal doublet, the 2 different materials can delaminate and fall apart.

When delamination occurs, moisture can also come between the layers and affect the colour of the opal. At Australian Opal Cutters, any delamination concern is assessed individually. Depending on the age, condition and cause, rights or remedies may apply under the Australian Consumer Law and our additional Two-Year Manufacturer’s Warranty. Our Lifetime Care & Service Program is a maintenance and service program and is not a lifetime warranty. Full terms are available in our Warranty, Lifetime Care & Jewellery Repair Policy.

Triplets are a doublet with a crystal quartz cap on the top which acts to magnify and enhance the colour of the opal and provide a strong resilient “cap”.

The existence of doublets and triplets allows for opal to reach a broader market. For instance, if we take the price of a triplet, it might be under $500, yet an Opal with exactly the same colour would be between 10 to 30 times more than the opal triplet with the same size and colour.

How Are These ‘Doublets’ and ‘Triplets’ Formed?

Triplets are approximately around 1/40th the price of a black opal, making them affordable alternatives to more expensive subcategories of opal. This is because

they are composed of different layers of opal and stone, rather than a ‘solid’ piece. Usually there is a thin layer of crystal opal coupled with a layer of potch (black common opal) or ironstone on the back, which acts to bring out the colour of the opal and capped with a Quartz crystal cap (for strength and colour magnification).

An opal triplet has a domed quartz crystal cap which has a higher reflective index than the opal. It can intensify the appearance of the colours and, because it is a cabochon, can magnify the pattern of the opal. Triplets have a quartz cap on the surface of the stone that acts to magnify and enhance the colour of the opal. Their layered construction can provide an affordable and durable way to enjoy natural opal when correctly made and cared for.

Quality materials and bonding methods are intended to reduce the risk of delamination, but no blanket lifetime guarantee applies. Delamination can occur in inferior or damaged products when moisture, ageing, heat, incompatible materials or failure of the adhesive affects the bond between layers. If an Australian Opal Cutters doublet or triplet develops a bonding issue, we will inspect the item and assess the cause under the Australian Consumer Law, our Two-Year Manufacturer’s Warranty and, where relevant, our repair service. Using silica-based glues and compatible materials helps reduce movement between layers over time. If a manufacturer puts plastic or other unsuitable material on the back of a triplet, the jewellery may eventually undergo a process of delamination. When the Opal heats and cools, plastic can expand and contract at a different rate to the Opal layer, placing stress on the bond.

Allowing moisture to attack and settle within the layers of the Triplet can affect the colour, value, integrity and appeal of the opal itself. Different backing materials can have different coefficients of expansion to opal, meaning that they may expand and contract at different rates and contribute to delamination.

Australian Opal Cutters uses suitable backing materials and modern bonding methods when manufacturing assembled opals. If a bonding concern arises, it is assessed individually in accordance with our Warranty, Lifetime Care & Jewellery Repair Policy rather than under a lifetime delamination guarantee.

Opal Doublets

A doublet is a thin layer of crystal opal with a layer of ‘potch’ (black common opal) or ironstone on the back which acts to bring out the colour of the opal.

Opal doublets use materials selected for compatible expansion and contraction. This helps reduce stress on the bond and the risk of delamination. The colour display of our opal triplets and our opal doublets is determined by the quality of the rough opal used to make them.

The search for suitable rough opal is ongoing and it is always a challenge to find the top gem opal required to produce the stunning colour and pattern found in our ‘A’ grade opal doublets and triplets.

Opal Triplets

An opal triplet is a doublet with a crystal quartz cap on the top (which acts to magnify and enhance the colour of the opal) giving it a strong and protective ‘cap’. We select compatible materials and bonding methods to make the construction durable; any later delamination or bonding concern is assessed individually rather than covered by a blanket lifetime guarantee.

The domed quartz crystal cap has a higher ‘refractive index rating’ which makes the triplet look incredible yet costs less than 1/30th the price of a solid black opal of the same size and colour.

Opal Triplet Cutting

Not all opal is suitable to be cut into doublets or triplets. In fact, only some opal fields will produce opal that is suitable for these kinds of projects. This means that any opal sourced must be carefully picked.

The rough opal is then prepared for slicing by removing the excess potch (a name given to colourless opal) on a diamond lapping wheel. Such opal then must be prepared for slicing; this ‘preparation’ encompasses a broad range of procedures, that differ depending on the size and shape of the natural opal.

After the opal is prepared, they are then mounted onto a ‘block’ that fits onto the slicing machine. This then allows for the opals to be sliced into thin pieces using this machine. The grey abrasive compound that works along with a blade made up of multiple thinly-spaced parallel blades are used to ‘cut’ the opal. Once done, these slices come out of the machine, and are ready to be blackened on one side, and mounted onto a glass backing.

Surface ‘cabochons’ made of glass or crystal are then carefully bonded onto the sliced opals and are custom-made according to the size, shape, and quality of the opal’s colour. All of this must be taken into account in order to get the best out of this opal. The triplets are then carefully cut out of the glass slides, where excess glass and potch is discarded.

The triplets are then glued onto ‘dop sticks’, which allows for excess glass that is found around the cabochons to be removed and shaped on a diamond wheel. This allows for the edges to be cohesive, especially after being finished on the ‘finishing wheel’.

Once all of this has been completed, the finished triplets are removed from the ‘dop sticks’, and then sorted based on sizes. These pieces then must be graded according to colour, quality, and clarity, before being used in jewellery.