Opal doublets and triplets can be a fantastic alternative to solid stones as they are much cheaper than solid black opals. Solid opals with the same appearance as an opal triplet can be ten times the price as they are rare and valuable, therefore they serve a useful purpose in making beautiful dark opals affordable. However, you need to be aware of what you are buying, and know how to correctly care for doublets and triplets to avoid water damage.
Opal Doublets and Triplets FAQ : What is a doublet opal? What is a triplet opal? What is the difference between doublets, triplets, and solid opals? What happens when doublets or triplets get wet? Why do some opals go cloudy? How should I care for a doublet or triplet?
Different types of matrix opals come from a variety of fields. Boulder matrix comes from the Queensland fields in the northern part of the opal regions in Australia. There is another form of matrix opal from Andamooka in South Australia which is treated to give it a darker background.
Because triplet opals have a clear non-opal capping on top, it is easy for an experienced person to identify a triplet immediately by the appearance of the stone. Triplets usually have a 'glassy' appearance and the light reflects differently from the top of the stone.