The Crystal Cove

October - Opal

October Birthstone - Opal 


The lists of gemstones by both The National Association of Goldsmiths in 1937 and The Jewelers of America in 1912 list opal as the traditional birthstone representing the month of October.  Both of these lists also associate pink tourmaline with the month of October and this has also been adopted by Swarovski® in addition to opal to represent their crystal alternatives to gemstones.



As well as being the birthstone for October, opal is also a traditional gift to celebrate the 14th year of marriage.  The word opal literally means "precious stone” and is a fascinating and unique stone making it a popular choice in many jewellery items today.  


Opal was once a gemstone of the Kings, second only to emeralds.  However, opal has gained many negative connotations over the recent centuries which still endure today, with some believing it to be bad luck or bad luck to wear if you were not born during the month of October. 

It has been suggested that diamond traders were responsible for spreading this rumour and it stuck.  Perhaps they were threatened by the mystic beauty and fascination of the lovely stone.  Also, in the 1829 novel "Anne of Geierstein” written by Sir Walter Scott, the heroin wore an opal which changed colour along with her mood.  When touched by holy water the opal discoloured and after being accused of being a demon as a result, she later dies.  This story is said to have had a huge negative impact on the public and opal prices dropped drastically.  

However, historically opal has been associated with and worn for many positive reasons.  For example, it is associated with health, beauty and purity and was once said to be worn to help improve eyesight.   




Opal is formed, over very long periods of time, with a mixture of water and silica picked up by the water as it runs through the earth into natural gaps under the earth surface.  It is the layers of the silica spheres built up over time which make opal such a fascinating and unique gemstone since the structure and gaps left between the spheres is how the opal displays it’s colour.  


The refraction of light through the silica spheres and the gaps between them, containing a water and silica solution, are how we see the colours of an opal and also the reason why opals can be seen in so many colours and even how we can see an individual opal in different colours if we move the stone and look at it from different angles.  This is known as a play of colour.    


So the colour of an opal involves white light split and colours of the rainbow are displayed.  Of course, not all opals will display all colours because of the structure of and gaps between the spheres.  Therefore opals can be found in just about any colour of the rainbow.  The most commonly found is blue opal with the most rare being opals which display a red colour.  Opals displaying red are able to display the other colours, blue, green, yellow and orange making them desirable. 


It is estimated that up to 90% of the world’s precious opal is found in Australia. It is found in smaller amounts in other places around the world such as Brazil, Czech Republic, Ethiopia and USA. 


Discovered in Southern Australia inside a fossil is the world’s finest opal "The Virgin Rainbow”.  This opal quite literally glows in the dark with vivid colours which intensify when there is less light around the stone