Each calendar month has a gemstone that is allied to it and this is called the birthstone. Each of us has a birthstone depending on the month in which we were born. The great thing about these gemstones is that the gemstones for each month have different and unique meanings and the October birthstone of opal is no exception.

As well as being the birthstone for October the opal is also the recognised gemstone for the thirteenth wedding anniversary. Most opals that we see for sale today are over 50 million years old and date back to the period in history when dinosaurs roamed the world. Opals are formed when decomposing rocks are mixed with ground water to form a silica gel, which then hardens. There are also two very
distinct types of opal stone, the common stone and the precious stone. Each type is determined by the way that the silica particles form in the stone. In precious opals the layers of silica are formed in rows and layers and this allows the diffraction of light to form fantastic flashes of colour, referred to as the fire.

Opals come from all over the world but the best concentration can be found in Australia. They can also be bought in many different and fabulous colours, including the black opal, which is the most rare type of opal. This type can even cost more than some diamonds! Giving a gift of an opal for a birthstone present is a lovely idea. Opals are pretty gemstones with a personality all their own. They are also quite unique in the world of gemstones.