If you take a look at an opal photograph on the web or in a book, it rarely does justice to the actual gemstone.
That’s because the play of color is really only visibile when the gemstone is moving.
Usually, the color is captured but the play of color is missed.
One method to capture an opal at its best is to submerge it in water. (Of course, you’d only do this with real opal, not doublets or triplets). This results in all of the opals showing simultaneously.
Take photos of dark stoneson a white background, and white or crystal opals on a black background. Increase the exposure a little bit to compensate for a lack of light.
Of course, the best way to photograph an opal is with a video camera, so that the complete play of color can be captured.
A double is a slice of natural opal glued to potch (common opal), glass, or some other base material. Triplets consist of a slice of opal glued between a base on the bottom and a piece of crystal or glass top.
(Note that if a cutter leaves some potch on tbhe bottom of a light or black opal, , that isn’t a doublet. It’s only if the opal is actually glued onto the potch - with the subsequent possibility of falling off as the glue degrades over time - that it is a doublet.
Although doublets are available, triplets are the most popular form of assembled opal. It used to be that triplets were assembled with quartz tops, opal centers, and potch bottoms. Today, it’s typically slivers of opal between two pieces of glass. The old-fashioned way was much sturdier - quartz being sturdier than glass - but the new way is more inexpensive.
Doublets were first made in Austria in 1946. Triplets began being made around 1960.
Although doublet and triplet jewelry can be quite attractive, make sure that you don’t immerse them in water, and be careful about knocking it into any furniture, as the glass ay break.