Opals are expensive and opal miners and opal cutters like to make even the thinnest or smallest piece of opal stone into something that will sell and look good in jewelry.An opal cutter begins with a piece of opal and he or she wishes to make it into a particular shape, most times that will be an oval, but there will be odd shapes like triangles and small chips left over so these small bits are polished as well in the hope that they can be sold as chips to be used in jewelry making somehow.But then sometimes a nice piece of opal will be so thin that it will break apart if we use it in a ring or other piece of jewelry. In that case the cutter can glue a piece of common opal , called potch, on the back of it and this will reinforce it so that it can be set in jewelry. These two pieces of opal glued together are now called something else - a doublet and another name for that is an opal product. Some people wishfully like to call it a reinforced opal but no matter how you think about it you cannot escape the fact that it is a doublet. Doublets are worth less than a solid opal.Sometimes the thin piece of opal is so thin that even a backing to reinforce it is not enough so the cutter puts a third piece on the first two. This third piece is usually a clear dome of quartz or perhaps glass or some other clear substance. This opal product is now called a triplet. Triplets are worth less than doublets.The last type of opal product is called mosaic. Mosaics are made by very patient and skilled people who get chips of bright colored opal and glue them together into intricate patterns and make them into jewelry or wall hangings. They are often magnificent and relatively cheap as they are mostly from cottage industry craftspeople. Opal composites are a great way to use what would otherwise be beautiful pieces of opal which would be dumped. They are also a good way for everyone to be able to afford a piece of opal jewelry.