A Triplet Opal is similar to a doublet opal in that it is a man made stack of different materials, including some real opal. In the case of a Triplet Opal, the slice of opal is generally paper thin.
This paper thin slice of opal is mounted on a dark background of stone or plastic in the same way that adoublet opals are, however a Triplet Opal then has a dome of clear crystal, glass or plastic over the top of the opal which has the effect of magnifying the colours.
Triplet Opals can make stunning pieces of jewelery, however they are easy to spot to an experienced person.
A Triplet Opal may have very bright colours, however the Play-Of-Colour will generally be poor. One benefit of Triplet Opals is that the clear dome will protect the opal from direct abrasion.
Triplet Opals are the least expensive form of opal since they contain only a very small amount of real opal. They can only be valued on the top down dimensions of a stone, rather than the carat weight, since plastic has no gemstone value. They are best mounted in silver or stainless steel jewellery.