loose opal gemstones on a black mat

Opal’s amazing display of colours and hypnotising patterns have earned it the title as one of the most beautiful gemstones in the world. Our ancient ancestors adored it and often associated it with the Gods. The Australian Aborigines believed it to be the Creator’s footprint, the Greeks thought it was formed by Zeus’ tears of joy and the Romans considered it to be a symbol of good fortune, hope and purity.

The gemstone has a kaleidoscopic display of colours, but how is it made and where does it come from?

Over 90% of the world’s opal come from Australia and it is the dry and arid landscape which is to thank for that. Opals are basically a hydrated form of silica, with silica being found in soil, sand and rock. Seasonal rains in the Outback soak deep into the underground carrying dissolved silica with it. During the dry periods that follow, the water evaporates leaving solid deposits of silica between layers of sedimentary rock. The silica deposits are retrieved and polished to give us the beautiful opal gemstone. In most cases water is still trapped in the silica crystals, so your opal gemstone may contain as much as 20% of water within.

Different Types of Opal

There are several different categories of opal with five main ones which include white, black, fire, boulder and crystal. Each one works with light differently and changes according to the background they are set against. For example, black opal shows a play of colour when placed against a dark background whereas white opals show a play of colour when placed against a light or grey background.

Other Interesting Facts About Opal

Opals have been with us for many, many centuries and we have learned a lot about them since. Queen Victoria had so many precious gemstones throughout her empire, but it is believed that opal was her utmost famous gem of them all. They are the birthstone of October with some believing them to be a lucky talisman or one that brings bad luck; such as the belief that it brings bad luck when worn by those who were not born in October. Though, that superstition seems to have stemmed from Sir Walter Scott’s novel “Anne of Geierstein”.

Arabic legends say it fell from the heavens in flashes of lightning with other cultures believing them to have supernatural powers such as the Greeks who believed it guarded the wearer from disease.

Our favourite description is that written by a Roman scholar known as Pliny: “Some opali carry such a play within them that they equal the deepest and richest colours of painters. Other simulate the flaming fire of burning sulphur and even the bright blaze of burning oil”.


Regardless of anyone’s belief, I’m sure we can all agree that opals are a fascinating gemstone and one whose changing colours almost have the power to mesmerise. We have a range of jewellery that incorporates opals as well as sell them loosely. Come by our workshop on 5 Mary Street, Dublin City Centre where you can see first-hand the mesmeric effects of its kaleidoscopic colours